Is There any Survival Benefit of Maintenance Chemotherapy Following Adjuvant Chemotherapy in Patients with Resected Pancreatic Cancer Patients with Post-Surgery Elevated CA 19-9?

BACKGROUND

Pancreatectomy offers only potential for cure but is only possible in a minority of patients. Even in those patients who receive adjuvant chemotherapy, majority of them succumb to death due to metastases. Radiation Therapy Oncology Group 9704 showed that post-surgery CA 19-9 levels are an important predictor of survival. European study group for pancreatic cancer-3 showed that completion of all 6 cycles of adjuvant chemotherapy was an independent prognostic factor. Any survival benefit of an intensified chemotherapy strategy has not been demonstrated in patients with persistently elevated CA 19-9 following surgery. The object of this study was to investigate any benefit of maintenance chemotherapy following adjuvant in these patients.

METHODS

Twenty patients with R0 surgery of pancreatic cancer who received adjuvant chemotherapy with post-surgery elevated CA 19-9 but no radiographic evidence of cancer was identified from 2005-2017. Either biopsy or positron emission tomography scan determined recurrence of cancer. Efficacy endpoints including overall survival and disease-free survival were assessed.

RESULTS

Maintenance and additional chemotherapeutic agents included 5-FU, capecitabine, platinum agents, irinotecan and nab-paclitaxel. CA 19-9 normalized in 3 patients while 22 persisted to be elevated or had further increase in the marker. Two patients underwent metastatectomy. Median disease-free survival was 14.5m (9-18), OS 29m (19-96) and OS rates were 80%, 50% at 1 and 2 years respectively.

CONCLUSIONS

We believe that the longer overall survival of our patients with elevated CA 19-9 post-surgery was due to maintenance and additional chemotherapy following planned 6-months of adjuvant therapy, close monitoring with monthly CA 19-9 and 3-monthly computed tomography scans. Our study also underlines importance of collecting pre-surgery CA 19-9 and complete staging including chest. Prospective study aiming to evaluate role of maintenance or intensified chemotherapy or targeted agents are indicated.