Evaluating Surgical Outcomes Between Estrogen Receptor Positive Invasive Lobular and Invasive Ductal Carcinoma of the Breast-A Propensity Matched Analysis.

INTRODUCTION: Invasive lobular carcinoma (ILC) contributes significantly to the global cancer burden and is the most common of the histological "special types" of breast cancer. ILC has unique features setting it apart from the more common invasive ductal carcinoma (IDC). Despite differences, treatment algorithms do not consider histological differences. AIM: To determine the differences in treatment and outcomes of ILC relative to IDC in a strict case-matched cohort study at a tertiary referral, specialist, breast cancer center. METHODS: All Estrogen receptor positive (ER+) ILCs from 1999 to 2015 were matched for; age, tumor size, grade, PR/HER2 status, nodal stage and metastases with ER+ IDCs from the same period. Surgical and systemic treatments were assessed along with overall (OS) and disease-free survival (DFS). RESULTS: 762 cases in total were analyzed (1:1 matching; ILC:IDC). ILC cases were more often treated with mastectomy (37.5% vs. 28.6%, P .009) and those who received breast conserving surgery (BCS) more often had an incomplete resection (30.2% vs. 19.6%, P .01). IDC were more often treated with NACT (5.5% vs. 14.4%, P < .001). Mean DFS were similar between ILC and IDC; 148.3 vs. 141.4 months (P .112) but OS was significantly longer in the ILC group; 165.7 vs. 134 months (P .002). This trend was consistent among the subset of patients undergoing BCS. For ILC undergoing BCS, mean DFS was 129.8 vs. 128.3 months for IDC (P .418) and OS was 155.4 and 110.7 months respectively (P < .001). Incomplete resection at the time of index surgery did not alter the disease free or overall survival in either the ILC or IDC patients to a level that reached statistical significance. CONCLUSION: In this cohort study, the strict matching of ILC and IDCs for a number of prognostic indicators, demonstrates the impact of lobular histology with a clarity not previously observed. ILCs have comparable survival outcomes to patients with IDC but at the expense of more extensive index and revisional surgery. There is a need for awareness of these facts among surgeons and patients for optimal treatment prioritization and provision.

Influence of neoadjuvant treatment strategy on perioperative outcomes in locally advanced rectal cancer.

AIM: Neoadjuvant chemoradiotherapy (nCRT) in locally advanced rectal cancer facilitates tumour downstaging and complete pathological response (pCR). The goal of neoadjuvant systemic chemotherapy (total neoadjuvant chemotherapy, TNT) is to further improve local and systemic control. While some patients forgo surgery, total mesorectal excision (TME) remains the standard of care. While TNT appears to be noninferior to nCRT with respect to short-term oncological outcomes few data exist on perioperative outcomes. Perioperative morbidity including anastomotic leaks is associated with a negative effect on oncological outcomes, probably due to a delay in proceeding to adjuvant therapy. Thus, we aimed to compare conversion rates, rates of sphincter-preserving surgery and anastomosis formation rates in patients undergoing rectal resection after either TNT or standard nCRT. METHODS: An institutional colorectal oncology database was searched from January 2018 to July 2023. Inclusion criteria comprised patients with histologically confirmed rectal cancer who had undergone neoadjuvant therapy and TME. Exclusion criteria comprised patients with a noncolorectal primary, those operated on emergently or who had local excision only. Outcomes evaluated included rates of conversion to open, sphincter-preserving surgery, anastomosis formation and anastomotic leak. RESULTS: A total of 119 patients were eligible for inclusion (60 with standard nCRT, 59 with TNT). There were no differences in rates of sphincter preservation or primary anastomosis formation between the groups. However, a significant increase in conversion to open (p = 0.03) and anastomotic leak (p = 0.03) was observed in the TNT cohort. CONCLUSION: In this series TNT appears to be associated with higher rates of conversion to open surgery and higher anastomotic leak rates. While larger studies will be required to confirm these findings, these factors should be considered alongside oncological benefits when selecting treatment strategies.

Relevance of the 21-gene expression assay in male breast cancer: A systematic review and meta-analysis.

INTRODUCTION: The 21-gene assay provides prognostication for estrogen receptor positive, human epidermal growth factor receptor-2 negative (ER+/HER2-) early female breast cancer patients. This signature has not been validated in male breast cancer (MBC). METHODS: A systematic review and meta-analysis was performed in accordance to the PRISMA guidelines. Retrospective cohort studies comparing 21-gene assay scores in female and MBC were included. Dichotomous variables were pooled as odds ratios (OR) and associated 95% confidence intervals (CI) using the Mantel-Haenszel method. RESULTS: Six studies including 176,338 patients were included (mean age of 63.4 years, range: 33-88). Of these, 1.0% had MBC (1826/176,338) and 99.0% were female patients (174,512/176,338). MBC patients were more likely to have increased tumour stage, nodal involvement, and grade 3 disease (all P < 0.001) In MBC patients, the mean score was 18.8 (range: 11-26) vs. 13.4 (range 0-33) in female patients (P < 0.001). In MBC patients, 22.4% had scores >30 (408/1822) versus 18.3% in female patients (31,852/174,500). In female patients, 52.0% had scores <18 (90,787/174,500) versus 47.8% in MBC (471/1822). Overall, patients with female patients were as likely to have scores <18 (OR: 1.04, 95% CI: 0.94-1.16), scores 18-30 (OR: 1.12, 95% CI: 1.00-1.26) and scores >30 (OR: 0.69, 95% CI: 0.45-1.07) as MBC patients. CONCLUSION: There are similar anticipated scores for female and MBC undergoing 21-gene expression assay testing for early stage, ER+/HER2-breast cancer. In the absence of stage matching, cautious interpretation of these results is required. Validation of the 21-gene assay in MBC is still required.