BACKGROUND:Mammographic breast density (BD) has garnered clinical interest due to its impact on breast cancer (BC) risk, sensitivity of mammographic screening, and tumour size at presentation. There is conflicting evidence as to BD's effect on re-excisions and recurrence following breast conserving surgery (BCS). We hypothesize that increasing BD may obscure disease, resulting in an underestimation of the extent of disease, and a greater risk of re-excision and local recurrence following BCS for invasive BC. METHODS:A retrospective, population-based review of patients undergoing BCS for invasive BC between January 1, 2010 and December 31, 2016 was performed. Patients undergoing mastectomy as primary management, previous or recurrent BC, or who were lost to follow-up were excluded. Patient age, BI-RADS score, treatments, and pathologic findings were analyzed by Pearson's Chi-Square or Fisher's exact test for categorical variables and the Kruskal-Wallis test for continuous variables. RESULTS:1371 and 1169 patients were eligible for re-excision and recurrence analysis, respectively. Higher BD is significantly associated with younger age, larger tumour size, and pathologic lymph node involvement. Multivariate analysis revealed no overall impact of BD on re-excision rate, though high BD (BI-RADS D vs A) was associated with a significant decrease re-excision rate (OR: 0.33, p ​= ​0.019). No influence of BD on disease recurrence was observed. CONCLUSION:Contrary to previous reports, high BD was associated with a decreased need for re-excision following BCS, which may be related to unmeasured factors. Increased BD was not associated with increased local disease recurrence.

Background: The status of the regional lymph node basin is of prognostic importance in patients with melanoma, making the performance of sentinel lymph node biopsies (SLNBs) a key component of patient care management, particularly with the advent of immunotherapy for adjuvant treatment. The primary goal of our study was to assess the false-negative rate of SLNBs among patients with melanoma.Methods: We conducted a retrospective review of patients with melanoma undergoing SLNB by a single surgeon between Jan. 1, 2005, and Dec. 31, 2020. We extracted and cross-referenced patient demographic and pathologic information.Results: During the study period, 501 patients underwent an SLNB. Of these, 97 (19.4%) patients had pathologically positive sentinel lymph nodes and 404 (80.6%) patients had negative results. The latter were subject to further review; 84 (20.8%) patients subsequently developed recurrence, with 25 (6.2%) recurrences within the primary nodal basin. Isolated regional recurrence occurred in 11 (2.7%) patients and conjunction with a false-negative rate was 10.2%. Unadjusted recurrence rates were similar across each lymph node basin, including the axilla (2.7%), groin (3.6%), and neck (1.4%).Conclusion: The false-negative SLNB rate was 10.2% for isolated regional recurrences. These findings need to be considered in the era of using adjuvant systemic therapy for patients with melanoma. Contexte: L'& eacute;tat du bassin ganglionnaire r & eacute;gional rev & ecirc;t une importance pronostique chez les personnes atteintes de m & eacute;lanome, ce qui rend les biopsies des ganglions sentinelles (BGS) essentielles & agrave; la prise en charge de la maladie, particuli & egrave;rement depuis l'av & egrave;nement de l'immunoth & eacute;rapie en traitement adjuvant. Le principal objectif de notre & eacute;tude & eacute;tait d'& eacute;valuer le taux de r & eacute;sultats faussement n & eacute;gatifs des BGS dans les cas de m & eacute;lanome.M & eacute;thodes: Nous avons proc & eacute;d & eacute; & agrave; une revue r & eacute;trospective des cas de m & eacute;lanome soumis & agrave; des BGS effectu & eacute;es par 1 seul membre de l'& eacute;quipe de chirurgie entre le 1er janvier 2005 et le 31 d & eacute;cembre 2020. Nous avons extrait et recoup & eacute; les donn & eacute;es d & eacute;mographiques et anatomopathologiques.R & eacute;sultats: Pendant la dur & eacute;e de l'& eacute;tude, 501 personnes ont subi des BGS. Parmi elles, 97 (19,4 %) pr & eacute;sentaient des ganglions sentinelles positifs & agrave; la biopsie et 404 (80,6 %) avaient des r & eacute;sultats n & eacute;gatifs. Ce dernier groupe a & eacute;t & eacute; soumis & agrave; un examen plus approfondi; 84 (20,8 %) ont par la suite pr & eacute;sent & eacute; des r & eacute;cidives, dont 25 (6,2 %) & agrave; l'int & eacute;rieur du bassin ganglionnaire primitif. Des r & eacute;cidives r & eacute;gionales isol & eacute;es sont survenues chez 11 (2,7 %) personnes et le recoupement avec le taux de r & eacute;sultats faussement n & eacute;gatifs a & eacute;t & eacute; de 10,2 %. Les taux de r & eacute;cidives non ajust & eacute;s ont & eacute;t & eacute; similaires peu importe les bassins ganglionnaires, y compris axillaires (2,7 %), inguinaux (3,6 %) et cervicaux (1,4 %).Conclusion: Le taux de r & eacute;sultats faussement n & eacute;gatifs des BGS a & eacute;t & eacute; de 10,2 % dans le cas des r & eacute;cidives r & eacute;gionales isol & eacute;es. Il faut interpr & eacute;ter ces r & eacute;sultats en tenant compte du fait qu'ils ont & eacute;t & eacute; recueillis & agrave; une & eacute;poque o & ugrave; les malades atteints de m & eacute;lanome & eacute;taient trait & eacute;s par chimioth & eacute;rapie adjuvante.

Background: This study evaluates population-based outcomes of patients with squamous cell carcinoma (SCC) of the nasal cavity treated in British Columbia. Methods: A retrospective review of nasal cavity SCC treated from 1984 to 2014 was performed (n = 159). Locoregional recurrence (LRR) and overall survival (OS) were evaluated. Results: The 3-year OS was 74.2% for radiation alone, 75.8% for surgery alone, and 78.4% for surgery and radiation (P = 0.16). The 3-year LRR was 28.4% for radiation alone, 28.2% for surgery alone, and 22.6% for surgery and radiation (P = 0.21). On multivariable analysis, surgery and postoperative radiation relative to surgery alone was associated with a lower risk of LRR (hazard ratio: 0.36, P = 0.03). Poor Eastern Cooperative Oncology Group status, node-positive, orbital invasion, smoking, and advanced age were associated with worse OS (all P <0.05). Conclusion: In this population-based analysis, multimodality treatment with surgery and adjuvant radiation were associated with improved locoregional control for SCC of the nasal cavity.

IntroductionPrevious studies have demonstrated an overall survival benefit with intraperitoneal chemotherapy in Stage III pelvic high-grade serous carcinoma (HGSC), but no studies have evaluated this treatment in early stage disease. We offered IP chemotherapy (IP/IV) to patients with Stage I-II HGSC from 2009–2022. The objectives are to evaluate time to recurrence (TTR), progression-free survival (PFS), and overall survival (OS) associated with IP/IV compared to standard intravenous (IV) chemotherapy.MethodsThis is a retrospective population-based cohort study of patients with stage I-II pelvic HGSC, who underwent primary surgery and adjuvant chemotherapy between 2009–2022. Statistical Analysis included Pearson’s Chi-square, Kaplan-Meier survival analysis, and Cox regression model to adjust for covariates.Results77 and 60 patients received IP/IV and IV chemotherapy, respectively. Those who received IP/IV were significantly younger. Stage distribution was similar between treatment groups. There were 24.7% and 5% confirmed BRCA mutation carriers, but 13% and 26.7% with unknown BRCA status in the IP/IV and IV groups, respectively. Five-year kaplan-meier outcomes were 77.7% vs. 67.7% TTR (p=0.49), 77.7% vs. 64.9% PFS (p=0.44), and 93.4% vs. 85.1% OS (p=0.29) in the IP/IV and IV groups, respectively. In multivariate analysis, IV chemotherapy trended towards shorter TTR, and worse PFS and OS. Those with unknown BRCA status had significantly better outcomes than confirmed BRCA negative (see tables 1 and 2).Conclusion/ImplicationsThere are improved outcomes for patients with early stage HGSC who received IP/IV chemotherapy, although not statistically significant. The unknown BRCA status group could have unrecognized BRCA mutation carriers, possibly accounting for better outcomes than those without BRCA mutations.

Background:Glioblastoma (GBM) is associated with fatal outcomes and devastating neurological presentations especially impacting the elderly. Management remains controversial and representation in clinical trials poor. We generated 2 nomograms and a clinical decision making web tool using real-world data.Methods:Patients ≥60 years of age with histologically confirmed GBM (ICD-O-3 histology codes 9440/3, 9441/3, and 9442/3) diagnosed 2005-2015 were identified from the BC Cancer Registry (n = 822). Seven hundred and twenty-nine patients for which performance status was captured were included in the analysis. Age, performance and resection status, administration of radiation therapy (RT), and chemotherapy were reviewed. Nomograms predicting 6- and 12-month overall survival (OS) probability were developed using Cox proportional hazards regression internally validated by c-index. A web tool powered by JavaScript was developed to calculate the survival probability.Results:Median OS was 6.6 months (95% confidence interval [CI] 6-7.2 months). Management involved concurrent chemoradiation (34%), RT alone (42%), and chemo alone (2.3%). Twenty-one percent of patients did not receive treatment beyond surgical intervention. Age, performance status, extent of resection, chemotherapy, and RT administration were all significant independent predictors of OS. Patients <80 years old who received RT had a significant survival advantage, regardless of extent of resection (hazard ratio range from 0.22 to 0.60, CI 0.15-0.95). A nomogram was constructed from all 729 patients (Harrell's Concordance Index = 0.78 [CI 0.71-0.84]) with a second nomogram based on subgroup analysis of the 452 patients who underwent RT (Harrell's Concordance Index = 0.81 [CI 0.70-0.90]). An online calculator based on both nomograms was generated for clinical use.Conclusions:Two nomograms and accompanying web tool incorporating commonly captured clinical features were generated based on real-world data to optimize decision making in the clinic.

Purpose This study compares patient reported outcomes and treatment related complications during radiotherapy before (August 2019 -Feb 2020) versus during (March -October 2020) the COVID-19 pandemic. Materials and Methods The MD Anderson Symptom Inventory – Head & Neck Module was used to assess curative intent H&N cancer patients’ symptoms during radiotherapy. Results There were 158 patients in the pre-pandemic cohort and 137 patients in the pandemic cohort. There was a trend towards more patients requiring an enteral feeding during the pandemic (21% vs 30%, p = 0.07). Weight loss was higher during the pandemic (mean − 5.6% vs 6.8%, p = 0.03). On multivariate analysis, treatment during the pandemic was associated with higher symptom scores for coughing/choking while eating (2.7 vs 2.1, p = 0.013). Conclusions Complication rates during H&N radiotherapy during the COVID-19 pandemic were similar at our institution relative to the pre-pandemic era although weight loss was greater and patients reported more severe choking/coughing while eating.

Abstract Background:Based on randomized controlled trials demonstrating no survival benefit of axillary dissection in elderly breast cancer patients, the SSO/Choosing Wisely campaign recommended against the routine use of sentinel lymph node biopsy (SLNB) in clinically node negative patients aged ≥70 with estrogen receptor (ER) positive breast cancer in 2016. SLNB is still performed in >80% of such patients and we have previously shown that at our institution, SLNB positivity influences adjuvant therapy decisions in this population. In this study, we sought to validate the association of SLNB positivity and adjuvant treatment in a larger population-based cohort, and to evaluate the impact of this finding on oncologic outcomes. Methods:The Breast Cancer Outcome Unit (BCOU) prospectively collects demographic, pathologic, treatment and outcomes data on all patients referred to BC Cancer with breast cancer in British Columbia, Canada. Female patients aged ≥70 with newly diagnosed estrogen receptor-positive invasive breast cancer who underwent SLNB from 2010-2016 were included. Patients with HER2-positive disease or those treated with neoadjuvant therapy were excluded. Multivariable analysis was used to assess the effect of SLNB positivity on adjuvant treatment. Overall survival (OS) and breast cancer specific survival (BCSS) were assessed using Kaplan-Meier analysis and Cox regression was used to assess contribution of SLNB positivity and adjuvant treatment. A nomogram was created to model the effect of nodal positivity and adjuvant treatment on BCSS. Results:We identified 2580 patients who met study criteria with a median age of 75 and a median tumor size of 15 mm. SLNB was positive in 23%. Sixty-seven percent of patients had breast conserving surgery (BCS) and 62% of patients had RT (BCS 79%, mastectomy 25%). As systemic therapy 5% of patients had chemotherapy (CT) and 78% of patients had hormone therapy (HT). Use of adjuvant therapies was associated with SLNB positivity: Systemic therapy (HR = 2.4, 95% CI: 1.84-3.14, p <0.0001), RT (HR = 4.94, 95% CI: 3.91-6.25, p <0.0001) and nodal RT (HR = 61.4, 95% CI: 26.6-141.7, p <0.0001). The 5-year OS was 86% and BCSS was 96% with a median follow-up of 4.33 years (95% CI 4.21-4.47 years). There was improved BCSS with receipt of HT (HR 0.51 95% CI 0.301-0.875, p=0.0142) and worse BCSS with grade 3 vs grade 1 disease (HR 4.09, 95% CI 2.06-8.10, p<0.0001). Age, tumor size, status of SLNB and use of RT were not significant prognostic variables. Patients with a positive SLNB who did not receive any adjuvant therapy had lower BCSS (HR 3.22 95% CI 1.235-8.418, p=0.0168) than those with a negative SLNB. However, amongst those who received any combination of CT, HT and RT, there was no significant difference in BCSS regardless of nodal status. A nomogram was developed incorporating tumor size, grade, SLNB status and adjuvant treatment. Using the nomogram, patients aged 75-79 with T1, grade 1-2 tumors, with or without positive SLNB and treated with or without adjuvant therapy had 5-year BCSS ≥95%. The nomogram also indicated that 5-year BCSS was similar for patients with positive and negative SLNB for all combinations of tumor features when patients received HT. Conclusions:In this modern, population-based cohort of patients over 70 with ER-positive breast cancer, 5-year BCSS was excellent at 96%. Although the use of adjuvant treatment was associated with a positive SLNB, BCSS was not changed based on nodal status when patients received HT. Our results support the Choosing Wisely recommendations; SLNB can be safely omitted in elderly patients willing to take HT, and we advocate that SLNB can be omitted in low-risk patients aged ≥75 even in the absence of planned HT. Citation Format: Elaine McKevitt, Rona Cheifetz, Kimberly DeVries, Alison Laws, Rebecca Warburton, Lovedeep Gondara, Caroline Lohrisch, Alan Nichol. Sentinel node biopsy should not be routine in older patients with ER positive breast cancer [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PD4-02.

Abstract BACKGROUND Radiation therapy (RT) for brain metastases in patients with non-small cell lung cancer (NSCLC) has undergone considerable evolution but remains controversial. METHODS Records for 2212 patients with NSCLC who received RT to the brain at one of six locations between 1996-2016 were retrospectively analyzed. Data were obtained from the institutional cancer registry following ethics approval. Overall survival (OS) was calculated from diagnosis of lung cancer to death, and Kaplan-Meier curves were compared by Log-rank and Cox regression. RESULTS Median OS was 11.8 months (95%CI 11-12.6 months). Median age was 65, and 1254 patients (57%) were female. ECOG performance status at diagnosis was 0 (12%), 1 (31%), 2 (17%), 3 (14%), 4 (2%), and unknown (24%). Younger age (HR=0.99, 95%CI 0.98-0.99), female sex (HR=0.80, 95%CI 0.74-0.88), and better ECOG performance status (p< 0.0001) were associated with superior OS. There was better OS in 932 patients (42%) that received chemotherapy (HR=0.63, 95%CI 0.58-0.69) and 603 (27%) that underwent surgery (HR=0.55, 95%CI 0.50-0.61). 2004 patients (91%) received 1 RT course, while 208 (9%) received multiple courses in various combinations of whole brain RT (WBRT) and stereotactic radiosurgery (SRS). SRS (HR=0.70, 95%CI 0.57-0.86) and multiple RT courses (HR=0.55, 95%CI 0.46-0.65) were associated with better OS. Median time from primary diagnosis to brain RT was 2.5 months, and from end of first brain RT to death was 3.5 months. A longer diagnosis to brain RT interval was associated with better OS (HR=0.95, 95%CI 0.95-96). CONCLUSIONS NSCLC patients with brain metastases continue to face poor prognosis, particularly when lung cancer diagnosis to first brain RT interval is short. Our analysis revealed younger age, female sex, and better ECOG performance status as predictors of superior survival. SRS and multiple RT courses also revealed superior survival, likely the result of patient selection and hence interpreted with caution.

The SSO Choosing Wisely campaign recommended selective sentinel lymph node biopsy (SLNB) in clinically node-negative women aged ≥ 70 years with ER+ breast cancer. We sought to assess the association of SLNB positivity, adjuvant treatment, and survival in a population-based cohort. Women aged ≥ 70 years treated for ER+ HER2− breast cancer between 2010 and 2016 were identified in our prospective provincial database. Overall survival (OS) and breast cancer-specific survival (BCSS) were assessed using Kaplan–Meier analysis. Multivariable logistic regression was used to assess the association of SLNB positivity with use of adjuvant treatments and survival outcomes. We identified 2662 patients who met study criteria. SLNB was positive in 25%. Increased use of chemotherapy (ChT), hormone therapy (HT), and radiotherapy (RT) was significantly associated with SLNB positivity. Five-year OS was 86%, and BCSS was 96% with median follow-up of 4.3 years. BCSS was worse with grade 3 disease (HR 4.1, 95% CI 2.1–8.1, p < 0.0001) and better with HT (HR 0.5 95% CI 0.3–0.9, p = 0.01). Patients with a positive SLNB treated without adjuvant therapy had lower BCSS (HR 3.2 95% CI 1.2–8.4, p = 0.017) than those with a negative SLNB, but patients with a positive SLNB treated with any combination of ChT, HT, and/or RT, had similar BCSS to those with a negative SLNB. BCSS in this population was excellent at 96%, and BCSS was similar with negative and positive SLNB when patients received HT. SLNB can be omitted in elderly patients willing to take HT.

OBJECTIVES:Head and neck (H&N) cancer patients experience significant acute side effects from treatment. This study evaluates prospectively collected patient-reported outcomes (PROs) in H&N patients undergoing radiotherapy (RT) to assess feasibility of electronically collecting PROs and to objectively document symptom acuity and trajectory during RT.MATERIALS AND METHODS:H&N patients undergoing radical RT at our multicentre institution completed a 12-item partial survey of the Vanderbilt Head & Neck Symptom Survey 2.0 prior to RT and weekly on RT. Between October 2016 and October 2018, 318 of 333 patients completed a baseline survey and at least one weekly survey.RESULTS:The average number of weekly questionnaires completed was 5 (range 1-8). The mean maximum symptom scores were highest for dysgeusia (5.8/10), pain (5.4/10), mucositis (4.8/10), weight loss due to swallowing (4.5/10) and mucus causing choking/gagging (4.3/10). On multivariate analysis, female gender, sinonasal, nasopharynx and oropharynx primaries were associated with a greater risk of moderate-severe pain (p < 0.05). Sinonasal, nasopharynx, oral cavity, oropharynx and thyroid primaries were associated with a greater risk of moderate-severe mucositis during radiation (p < 0.0001). Salivary gland, sinonasal, nasopharynx and oropharynx primaries and higher radiation dose were associated with a greater risk of moderate-severe dysgeusia (all p < 0.05).CONCLUSIONS:Electronic PRO collection during H&N cancer RT is feasible. H&N cancer patients experience significant symptoms during RT, and the most severe symptoms reported were dysgeusia, pain and mucositis. Oropharynx cancer patients reported the highest symptom scores during RT.

PURPOSE:To evaluate the predictive value of FDG-PET/CT for detection of residual disease after radical radiotherapy for patients with squamous cell carcinoma (SCC) of the oropharynx, comparing p16 positive (+) versus p16 negative (-) disease. METHODS AND MATERIALS:A retrospective analysis of patients with SCC of the oropharynx at our institution treated with radical radiotherapy between 2012 and 2016 was performed. The primary and lymph node metabolic responses were evaluated independently on the post-treatment FDG-PET/CT. The reference standard was pathology when available, subsequent post-treatment FDG-PET/CT results or clinical follow-up. RESULTS:Median follow-up time was 32 (30-34) months. 556 patients had p16+ disease and 92 had p16- disease. The median time of post-treatment FDG-PET/CT was 96 (45-744) days after radiotherapy completion: 68% had complete metabolic response (CMR) defined as mild non-focal or no uptake, 10% residual primary disease, 11% residual regional lymph node disease, 5% residual primary and regional disease, and 6% distant metastatic disease. The local positive predictive value (PPV) was 26% for p16+ versus 54% for p16- (p = 0.01) and the regional PPV was 31% for p16+ versus 58% for p16- (p = 0.01). The local negative predictive value (NPV) was 100% regardless of p16 status and the regional NPV was 100% for p16+ versus 99% for p16- (p = 0.33). For p16+ cases, regional specificity was 76.2% versus 91.1% (p = 0.0003), local PPV was 0 versus 30% (p = 0.06) and the regional PPV was 12% versus 35% (p = 0.06) for FDG-PET/CT scans performed at ≤12 weeks versus >12 weeks. Five-year overall survival for those with CMR was 87% versus 51% without CMR (p ≤ 0.001). CONCLUSIONS:Metabolic response on post-treatment FDG-PET/CT has excellent NPV regardless of p16 status. The PPV is significantly lower in those with p16+ versus p16- disease, with a significantly reduced regional specificity and a trend towards inferior predictive value if performed ≤12 weeks. CMR predicts for a significantly improved overall survival.

Background: Normal fibroglandular tissue appears white on a mammogram and is described as dense; fatty tissue appears dark and is described as non-dense. Increased breast density is associated with greater breast cancer risk. Increased breast density also reduces the sensitivity of mammography to reveal changes associated with cancer, a concern referred to as masking. Interval breast cancers are those diagnosed between screening visits and are more common in women with dense breasts. The effects of breast density have been the subject of much research, but the results are often summarized in ways that do not facilitate understanding for referring physicians and screening participants. An analysis of data from the BC Cancer Breast Screening Program was proposed to assess the influence of breast density on the risk of cancer and on breast cancer prognostic factors. Methods: Although density scores were not required prior to 2018, many BC Cancer Breast Screening Program centres assigned and recorded this information. Two study samples were abstracted from the Breast Screening Program database to achieve four study objectives. Sample 1 data included mammograms of participants age 40 to 74 obtained in 2017 using digital mammography and assigned density categories according to the Breast Imaging-Reporting and Data System (BI-RADS): A (least dense), B, C, or D (most dense). Sample 1 data were used to describe the distribution of BI-RADS breast density in the screening population (Objective 1). A subset of Sample 1 data was used to examine the stability of BI-RADS density categories assigned (Objective 2). Sample 2 data included mammograms performed from 2011 to 2015. Data from this period were used to examine the influence of density on the risk of breast cancer development (Objective 3) and the effect of density on prognostic factors such as tumor size and lymph node involvement (Objective 4). The 2011 to 2015 data collection period was chosen so that notification of any cancer cases to the BC Cancer Registry was complete and 5 years of data could be analyzed. The screening history of each participant in Sample 2 was assessed by screening rounds. Screening rounds that followed an abnormal result were excluded from the analysis as participants were likely subject to further testing prior to returning to screening, and their cases would not necessarily reflect the influence of density on mammography performance. A breast cancer was defined as screen-detected if it was diagnosed in the 12 months following an abnormal screening mammogram. All breast cancers not classified as screen-detected were defined as interval cancers. Rates of screen-detected breast cancer and interval cancer were calculated and rates were estimated for participants at average risk and higher-than-average risk (i.e., having a family history of breast cancer in a first-degree relative). Results: Breast density data analyzed for 208925 BC Cancer Breast Screening Program participants were seen to vary by age, with a declining proportion of mammograms assigned BI-RADS C and D scores at increasing ages. Density also varied by ethnic group, with East Asian participants having denser breasts and First Nations participants the least dense breasts. Density did not vary by risk status. When 62887 mammogram pairs from 2017 and earlier were compared, concordance was lowest for mammograms with a BI-RADS score of D. The majority of participants did not have both mammograms read by the same radiologist and concordance was lower when different radiologists read the mammograms than when the same radiologist read both mammograms. Cancer risk was evaluated by looking at 649393 screening rounds for 388576 participants. Predicted rates of interval and screen-detected cancer were calculated for women of average risk screened on a biennial (currently recommended) basis and for women of higher-than-average risk screened on an annual (currently recommended) basis. Risk of screen-detected cancer was seen to increase with age and to vary with BI-RADS density for both average-risk and higher-than-average-riskwomen. Risk of interval cancer also increased with BI-RADS density and with age for average-risk and higher-than-average-risk women. Prognostic factors were tabulated separately for biennial screen-detected cancers and interval cancers. Screen-detected cancers were smaller than interval cancers and less likely to have nodal involvement. Similarly, tumor size increased among interval cancers with increasing density, but the likelihood of nodal involvement did not. Conclusions: Other studies report similar findings to those described here, with density declining with age, higher density seen in screening participants of East Asian heritage, instability in density categorization on consecutive mammograms, and instability increasing when mammograms are interpreted by different radiologists. When discussing breast screening, breast density alone should not be seen as the primary determinant of breast cancer risk. Following a normal screening mammogram, a screening participant's risk of being diagnosed with an interval breast cancer over the next screening round increases with age and density, and is roughly similar at 1 year for women at elevated risk to that at 2 years for women at non-elevated risk. Further research is needed to elucidate the specific benefits of the increased cancer detection afforded by supplemental testing for screening participants found to have dense breasts.

Background: Normal fibroglandular tissue appears white on a mammogram and is described as dense; fatty tissue appears dark and is described as nondense. Increased breast density is associated with greater breast cancer risk. Increased breast density also reduces the sensitivity of mammography to reveal changes associated with cancer, a concern referred to as masking. Interval breast cancers are those diagnosed between screening visits and are more common in women with dense breasts. The effects of breast density have been the subject of much research, but the results are often summarized in ways that do not facilitate understanding for referring physicians and screening participants. An analysis of data from the BC Cancer Breast Screening Program was proposed to assess the influence of breast density on the risk of cancer and on breast cancer prognostic factors. Methods: Although density scores were not required prior to 2018, many BC Cancer Breast Screening Program centres assigned and recorded this information. Two study samples were abstracted from the Breast Screening Program database to achieve four study objectives. Sample 1 data included mammograms of participants age 40 to 74 obtained in 2017 using digital mammography and assigned density categories according to the Breast Imaging-Reporting and Data System (BI-RADS): A (least dense), B, C, or D (most dense). Sample 1 data were used to describe the distribution of BI-RADS breast density in the screening population (Objective 1). A subset of Sample 1 data was used to examine the stability of BI-RADS density categories assigned (Objective 2). Sample 2 data included mammograms performed from 2011 to 2015. Data from this period were used to examine the influence of density on the risk of breast cancer development (Objective 3) and the effect of density on prognostic factors such as tumor size and lymph node involvement (Objective 4). The 2011 to 2015 data collection period was chosen so that notification of any cancer cases to the BC Cancer Registry was complete and 5 years of data could be analyzed. The screening history of each participant in Sample 2 was assessed by screening rounds. Screening rounds that followed an abnormal result were excluded from the analysis as participants were likely subject to further testing prior to returning to screening, and their cases would not necessarily reflect the influence of density on mammography performance. A breast cancer was defined as screen-detected if it was diagnosed in the 12 months following an abnormal screening mammogram. All breast cancers not classified as screen-detected were defined as interval cancers. Rates of screen-detected breast cancer and interval cancer were calculated and rates were estimated for participants at average risk and higher-thanaverage risk (i.e., having a family history of breast cancer in a first-degree relative). Colin Mar, MD, Janette Sam, MRT, Colleen E. McGahan, MSc, Kimberly DeVries, MSc, Andrew J. Coldman, PhD The influence of breast density on breast cancer diagnosis: A study of participants in the BC Cancer Breast Screening Program A screening participant’s risk of being diagnosed with an interval breast cancer following a normal screening mammogram was found to increase with age and density, and to be roughly similar at 1 year for women at higher-than-average risk (first degree family history of breast cancer) to that at 2 years for women at average risk. Dr Mar is medical director of the BC Cancer Breast Screening Program. Ms Sam is operations director of the BC Cancer Breast Screening Program. Ms McGahan is director of Cancer Surveillance and Outcomes, BC Cancer. Ms DeVries is a biostatistician in Cancer Surveillance and Outcomes, BC Cancer. Dr Coldman is an emeritus scientist in Cancer Control Research, BC Cancer. This article has been peer reviewed.

Abstract PURPOSE Glioblastomas (GBM) are the most common primary brain tumour recurring in most patients despite maximal management. Patient selection for appropriate treatment modality remains challenging resulting in heterogeneity in management. We examined the patterns of failure and developed a scoring system for patient stratification to optimise clinical decision making. METHODS 822 adults (BC Cancer Agency registry) diagnosed 2005–2015 age ≥60 with histologically confirmed GBM ICD-O-3 codes (9440/3, 9441/3, 9442/3) were reviewed. Univariate and Kaplan-Meier analysis were performed. Performance status (PS), age and resection status were assigned a score, cummulative maximal (favorable) score of 10 and minimum (unfavorable) score of 3. Patterns of failure were further analysed in the subset of patients with radiographic follow-up. RESULTS PS score of 3(KPS >80, ECOG 0/1), 2 (KPS 60–70, ECOG 2), 1 (KPS < 60, ECOG 3/4) (median OS 11, 6, 3 months respectively), age score and resection status were prognostic for OS with PS resulting in the most significant curve separation (p< 0.0001). Biopsy as compared to STR/GTR resulted in poorer OS in patients over 70 (age score 1/2) but had less impact in patients younger than 70 (age scores 3/4). The median OS for cumulative scores of 9/10 (123 patients), 7/8 (286 patients), 5/6 (313 patients), and 3/4 (55 patients) were 14, 8, 4 and 2 months respectively (p< 0.0001) allowing for stratification into 4 prognostic groups. 133 patients had >3 MRIs following diagnosis allowing for clinical and radiographic analysis of progression. Clinical/radiographic progression occurred within 3 months (29%/45%), 6 months (50%/66%), 9 months (70%/81%). Progression type (radiographic, clinical, both was not associated with OS. CONCLUSION Our novel prognostic scoring system is effective in achieving patient stratification and may guide clinical decision making. Early radiographic progression appears to precede clinical deterioration and may represent true progression in the elderly.