A comparative biomarker study of 514 matched cases of male and female breast cancer reveals gender-specific biological differences.

Male breast cancer remains understudied despite evidence of rising incidence. Using a co-ordinated multi-centre approach, we present the first large scale biomarker study to define and compare hormone receptor profiles and survival between male and female invasive breast cancer. We defined and compared hormone receptor profiles and survival between 251 male and 263 female breast cancers matched for grade, age, and lymph node status. Tissue microarrays were immunostained for ERα, ERß1, -2, -5, PR, PRA, PRB and AR, augmented by HER2, CK5/6, 14, 18 and 19 to assist typing. Hierarchical clustering determined differential nature of influences between genders. Luminal A was the most common phenotype in both sexes. Luminal B and HER2 were not seen in males. Basal phenotype was infrequent in both. No differences in overall survival at 5 or 10 years were observed between genders. Notably, AR-positive luminal A male breast cancer had improved overall survival over female breast cancer at 5 (P = 0.01, HR = 0.39, 95% CI = 0.26-0.87) but not 10 years (P = 0.29, HR = 0.75, 95% CI = 0.46-1.26) and both 5 (P = 0.04, HR = 0.37, 95% CI = 0.07-0.97) and 10 years (P = 0.04, HR = 0.43, 95% CI = 0.12-0.97) in the unselected group. Hierarchical clustering revealed common clusters between genders including total PR-PRA-PRB and ERß1/2 clusters. A striking feature was the occurrence of ERα on distinct clusters between genders. In female breast cancer, ERα clustered with PR and its isoforms; in male breast cancer, ERα clustered with ERß isoforms and AR. Our data supports the hypothesis that breast cancer is biologically different in males and females suggesting implications for clinical management. With the incidence of male breast cancer increasing this provides impetus for further study.

Amiodarone lung: under recognised but not forgotten.

Amiodarone is a common medication used widely in clinical practice. It is a triiodinated antiarrhythmic associated with a variety of adverse effects both pulmonary and extrapulmonary, the most serious being amiodarone-induced pulmonary toxicity (AIPT) or amiodarone lung. This can present with a variety of clinical syndromes ranging from subacute symptoms to an indolent and a progressive course thus mimicking an alternative diagnosis. We report a case of amiodarone lung in a female who presented with an acute fulminant progressive pneumonitis despite being on very low dose (100 mg once daily) that proved fatal. Diagnosis was made on postmortem examination due to a diagnostic conundrum. Despite the steady decrease of AIPT with reduced dose, it is vital for the treating clinicians to monitor regularly for adverse effects and review the need for long-term use to prevent complications.