Extent and distribution of peritoneal disease in patients undergoing cytoreductive surgery for first platinum sensitive recurrence in ovarian cancer and its potential therapeutic implications.

BACKGROUND

Selected patients with platinum sensitive recurrent ovarian cancer may benefit from cytoreductive surgery (CRS). The aim was to study the pattern of peritoneal involvement in these patients that has not been done before.

METHODS

A comparison was made between the surgical and pathological findings in 60 patients undergoing salvage CRS from July 2018 to December 2019. The sites of residual disease, correlation with surgical and pathological peritoneal cancer index (PCI), small bowel involvement and regional lymph node involvement were studied.

RESULTS

Fifty-eight (96.6%) had serous carcinoma and 2 (3.4%) clear cell carcinoma. The median surgical PCI (sPCI) was 7 [range 0-27] and median pathological PCI (pPCI) 4 [range 0-21]. CC-0 resection was performed in 81.6%. The upper regions (region 1,2,3) were the commonest sites of residual disease (63.3%) followed by lower regions (region 5,6,7) in 55.0%, middle regions (regions 0,4,8) in 53.3% and small bowel regions (regions 9-12) in 26.6%. Small bowel involvement was associated with a higher sPCI and pPCI (p < 0.001 for both). Regional nodes were involved in 46.6%. A pathological complete response was seen in 8 (13.3%) patients of which 2 had residual disease in regional nodes. Microscopic disease in 'normal appearing' peritoneum was seen in 21%.

CONCLUSIONS

The parietal peritoneum was the commonest site of recurrence. Small bowel involvement occurred late and was associated with more extensive disease. Regional lymph node involvement was seen nearly 50% and was a common site for occult disease. The role of more extensive parietal peritoneal resection for recurrent disease should be evaluated prospectively.