The importance of gender in patients with peritoneal metastases of appendiceal origin treated by cytoreduction and intraperitoneal chemotherapy: an analysis of 257 consecutive patients from an Australian centre.

BACKGROUND AND OBJECTIVES: In the setting of colorectal cancer, female gender has been associated with superior long-term outcomes. Our aim is to investigate the gender differences for metastatic epithelial neoplasms of the appendix treated by cytoreductive surgery (CS) and intraperitoneal chemotherapy (IPC).

METHODS: The survival outcomes of patients treated with CS/IPC from 1996 to 2013 at St. George Hospital, Sydney, Australia, for peritoneal metastases of appendiceal origin were retrospectively analysed.

RESULTS: Two hundred and fifty-seven consecutive patients were followed for a median of 35.3 months. Baseline characteristics between genders were comparable, including age (p = 0.13) and peritoneal cancer index (p = 0.94). Median overall survival (OS) and progression-free survival (PFS) was not reached (NR) and 44.4 months, with a 3-, 5- and 10-year survival of 82, 74 and 64 %. OS and PFS for females was NR and 50.7 months, compared to NR (p = 0.007) and 31.5 months for males (p = 0.07). Three-, 5- and 10-year survival rates for females were 88, 84 and 72 % compared to 74, 61 and 53 % for males.

CONCLUSION: Observed gender differences for neoplasms of the appendix may direct future research in gender-specific tumour markers and the development of adjuvant therapies to improve patient outcomes.