Relationship between peritoneal washing cytology through implantable port system (IPS-cytology) and second-look laparotomy in ovarian cancer patients with unmeasurable residual diseases.

OBJECTIVE

Intraperitoneal chemotherapy for minimal residual ovarian cancer has been shown to be effective. However, evaluation of the response without a second-look laparotomy (SLL) is impossible because such disease is unmeasurable by radiographic studies. In this prospective pilot study, we evaluated the relationship between implantable port system (IPS)-cytology and findings by SLL in patients with unmeasurable diseases.

METHODS

Patients eligible for this study were those who had either unmeasurable residual disease at the time of initial surgery or measurable residual disease which became unmeasurable before second-look laparotomy. At the time of the initial surgery, the IPS was placed and intraperitoneal chemotherapy was administered. To obtain IPS-cytology, approximately 500 ml of saline was infused, with the patients changing their position to wash the peritoneal surface as thoroughly as possible. More than 20 ml of saline was recovered for cytological evaluation. SLL was performed after 4 to 10 courses of chemotherapy. Results of IPS-cytology obtained immediately before SLL and the SLL findings were compared.

RESULTS

Forty-four patients were entered into this study. Twenty-nine patients had unmeasurable residual disease at the time of initial surgery and 15 had measurable residual disease which became unmeasurable before SLL. Only 40 patients were eligible for evaluation because catheter failure occurred in 4 patients. Three of the 26 patients who had negative IPS-cytology results were found to have positive SLL results. All 14 patients who had positive IPS-cytology results also had positive SLL results.

CONCLUSIONS

IPS-cytology can detect intraperitoneal persistent disease in patients with unmeasurable residual ovarian cancer. Persistent positive IPS-cytology can indicate a negative response to chemotherapy, thus making it possible to avoid SLL. Further study with a larger number of patients is required to determine the role of negative IPS-cytology.