Abstract P1-23-03: Male breast cancer in a retrospective study from the Maria Sklodowska Curie National Research Institute of Oncology in Warsaw, Poland

Background: Male breast cancer is a rare disease accounting for less than 1% of all breast cancer diagnoses worldwide. Male breast cancer is not very well understood. Prospective data in the management of male breast cancer are lacking and majority of treatment strategies are adopted from the established guidelines for breast cancer in women. The understanding of biology, clinical presentation, genetics, and management of MBC is evolving but there still remains a large knowledge gap due to the rarity of this disease.Patients and methods: The aim of this retrospective study is to analyze the epidemiologic, clinical and therapeutic problems with this disease and to compare some cancer aspects between male and female in 67 cases collected at Maria Sklodowska Curie National Research Institute of Oncology in Warsaw between 05.2011 and 02.2021. Patients with a primary diagnosis of breast cancer were identified in the our database.Results: The median age was 65 years (range 22-93 years). Family history was present in 15 (22%) men and in as 17 pts (25%) other cancer were diagnosed (prostate cancer, melanoma, Hodgkin lymphoma, NET, thyroid cancer). Early, locally advanced, and metastatic disease were seen in 44 (65%), 9 (14%), and 14 (21%) men, respectively. Majority (59, 88%) of men had invasive ductal carcinoma histology. In radically treated 44 men, neoadjuvant chemotherapy was given to 20 (29%) patients with pCR in 1 (1.5%) and neoadjuvant hormonotherapy (tamoxifen) in 5 (7.5%) of pts. Estrogen receptor, PR, and human epidermal growth factor receptor 2/neu positive were seen in 62 (92.5%), 60 (89.5%), and 15 (22%) patients, respectively. Triple negative breast cancer were diagnosed in 4 (6%) pts. During the follow-up period locoregional recurrence occurred in 1 (1.5%) and distant metastasis in 15 (22%) men, respectively. Bone was the most representative site of metastases (20, 69%). In contrast to women with breast cancer, who have mainly osteolytic metastases (75-80%), our analysis found that men were predominantly osteoblastic lesions (10, 50% pts with bone mts). There was 31 cases of death (46%). Death was usually due breast cancer progression (29, 43%).Conclusion: This analysis found that men with breast cancer had a higher risk of second primaries cancer. Bone was the most representative site of metastases, but they are mainly osteoblastic lesions.

Citation Format: Agnieszka Irena Jagiello-Gruszfeld, Pawel Winter, Rafal Wojcik, Michal Kunkiel, Renata Sienkiewicz, Roman Dubianski, Anna Majstrak-Hulewska, Zbigniew Nowecki. Male breast cancer in a retrospective study from the Maria Sklodowska Curie National Research Institute of Oncology in Warsaw, Poland [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P1-23-03.

“Good Risk”: low-risk patients with ductal carcinoma in situ (DCIS) benefit from whole breast radiotherapy after breast conservation surgery (BCS)–long-term follow-up

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Background: Identification of patients group with low risk DCIS that do not require radiation therapy after BCS is still a challenge. We assessed recurrence rates in patients with „good risk” DCIS with and without radiotherapy after BCS, and subsequently compared our results with the long-term data from RTOG 9804 trial [1]. Methods: Out of 737 patients with DCIS managed between 1996-2011 at the Cancer Center Warsaw, Poland, 400 were treated conservatively. Out of those 133 were classified as „good risk” patients in accordance with RTOG 9804 trial criteria (DCIS < 2.5 cm, mammographically detected, NG1/G2 with margin = > 3 mm). 79 patients received only BCS and another 54 patients were treated with BCS and radiotherapy. Competing risk of recurrence, DFS and OS were calculated for both groups. The results were compared with the long-term observation results of RTOG 9804 trial. Results: The competing risk of recurrence after 10 years in the group treated with BCS and in patients receiving BCS with radiotherapy was 26% and 6% respectively (p = 0.013). 10-year DFS was 58% and 88% (p = 0.02) and OS was 94% and 97% (p = 0.3) respectively. Based on the ASTRO Conference 2018, 10-year recurrence risk without and with radiotherapy in RTOG 9804 trial were 9.1% and 1.7% [1]. In our study in comparison to RTOG 9804 trial results, more patients had DCIS sized 1.1-2.5 cm, excision margins of 3-9 mm and no patient received adjuvant tamoxifen. Conclusions: Similarly to the results of RTOG 9804 trial [1], radiotherapy reduced recurrence rate in “good risk” DCIS, however, in our study the recurrence rate was higher - probably due to difference in risk factors and no tamoxifen use. 1.McCormick B et al. Randomized trial evaluating radiation following surgical excision for “Good Risk” DCIS: 12year report from NRG/RTOG 9804. ASTRO October 21, 2018.

Abstract P4-15-12: Evaluating the significance of the Van Nuys prognostic index for the management of ductal carcinoma in situ – one center's experience

Aim: This was to assess the treatment outcomes of ductal carcinoma of the breast (DCIS) based on the Van Nuys Prognostic Index.

Material and Methods: 634 consecutive patients with DCIS were treated at the Warsaw Cancer Center, Poland between 1996 and 2008 based on the VNPI score. Tumorectomy without radiotherapy (T) was performed in 123 (20%) patients, breast conserving treatment (BCT) in 206 (32%) and mastectomy (M) in 305 (48%). Disease-free survival (DFS) and overall survival (OS) were analysed within 3 groups and a multivariate analysis was performed to determine the most important factor affecting local relapse.

Results: 5-year, 10-year and 15-year DFS in the M group were respectively 98%, 97% and 97% whilst 5-year, 10-year and 15-year DFS in the BCT group were respectively 91%, 87% and 80%. 5-year, 10-year and 15-year DFS in the T group were respectively 92%, 73% and 67%. Local recurrence was observed in 54 patients. In 40% cases this was noninvasive and in 60 % invasive. Only 4 of 54 patients with recurrence died due to breast cancer. 5-year, 10-year and 15-year OS in the M group were respectively 96%, 92% and 89%. 5-year, 10-year and 15-year OS in the BCT group were respectively 99%, 94% and 85%. 5-year, 10-year and 15-year OS in the T group were respectively 95%, 90% and 73% (p=0.422). Tumor size assessed by mammography was the only variable affecting DFS.

Conclusions: Treatment outcomes of DCIS based on the Van Nuys Prognostic Index are comparable with those cited the literature, however, the recurrence rate in the T group seems to be very high. This group requires that new risk factors be sought for prior to taking a treatment decision.

Citation Format: Niwinska A, Galecki J, Nagadowska M, Piechocki J, Kunkiel M, Jagiello-Gruszfeld AI, Nowecki Z. Evaluating the significance of the Van Nuys prognostic index for the management of ductal carcinoma in situ – one center's experience [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P4-15-12.

Outcomes from 735 patients with breast cancer brain metastases (BM) according to biological subtype, number of BMs, and systemic treatment after local therapy

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Background: To assess survival when BM is detected according to the biological subtype of breast cancer, number of BMs and systemic treatment after local therapy. Methods: Subjects were 735 consecutive breast cancer patients with BM treated during 2003-2015. Whole brain radiotherapy was undertaken in 97%, neurosurgery -19% and systemic therapy was performed in 74% cases. The biological subtypes: triple-negative (TNBC), HER2+ER/PR-, HER2+/ER/PR+ and ER/PR+HER2- (Luminal) were determined in 714 subjects. Survival after BM detection was assessed in the entire group, in patients with a single BM (1 brain lesion regardless of metastases in other organs) and those with a solitary brain metastasis (1 brain lesion but no metastases in other organs). Factors influencing survival upon detecting BM were assessed by Cox multivariate analysis. Results: The median survivals for all patients with TNBC, HER2+ER/PR-, HER2+/ER/PR+ and Luminal breast cancer BM were respectively 4, 8, 10 and 9 months (p < 0.001). In those both treated and untreated systemically within the TNBC, HER2+ER/PR-, HER2+/ER/PR+ and Luminal subtypes survivals were correspondingly 6, 10, 14, 11 and 2, 3, 2, 2 months (p < 0.001). Median survivals of 171 patients with a single BM treated and untreated systemically were respectively 15 and 5 months (p < 0.001). Median survivals of 70 patients with solitary BM treated and untreated systemically were respectively 28 and 6 months (p < 0.001). In patients with solitary brain metastasis, median survival within the TNBC, HER2+ER/PR-, HER2+/ER/PR+ and Luminal subtypes, with systemic treatment was respectively 16, 28, 28, 28 months and without systemic treatment 6, 7, 7 and 7 months (p < 0.001). Conclusions: Patients with TNBC and BM had the worst prognosis. Systemic treatment performed after local therapy is an important factor prolonging survival of patients with breast cancer BM, even in those with solitary brain metastasis. Based on the present evidence and our recent publication, systemic treatment should be performed in all patients with BM after local treatment, even those with brain metastases as an isolated recurrence.