Utility of neoadjuvant CT with/without SBRT to improve outcomes of non-metastatic pancreatic cancer
PD-0893
Abstract
Utility of neoadjuvant CT with/without SBRT to improve outcomes of non-metastatic pancreatic cancer
Authors: Priyanka Pathare1, Dr. Reena Engineer1, Dr. Rahul Krishnatry2, Dr. Shivkumar Gudi1, Dr.Manish Bhandare3, Dr.Vikram Chaudhari3, Dr. Vikas Ostwal4, Dr. Anant Ramaswamy4, Dr. Shailesh Shrikhande3
1Tata Memorial Hospital, Radiation Oncology, Mumbai, India; 2Tata Memorial Hospital, Radiation oncology, Mumbai, India; 3Tata Memorial Hospital, Surgical Oncology, Mumbai, India; 4Tata Memorial Hospital, Medical Oncology, Mumbai, India
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Purpose or Objective
To evaluate the survival outcomes of all the non-metastatic resectable pancreatic cancer (RPC), borderline resectable pancreatic cancer (BRPC) and locally advanced pancreatic cancer (LAPC) pancreatic cancer patients.
Material and Methods
We analyzed all the consecutive patients diagnosed as carcinoma head of pancreas without metastasis treated at our center. RPC patients underwent upfront surgery with or without adjuvant treatment whereas the BRPC patients received neoadjuvant chemotherapy (NACT) with mFOLFIRINOX or NAB-PACLITAXEL (4-6 cycles) followed by surgical assessment. Patients with partial response (PR) were surgically explored, those with stable disease(SD)received stereotactic body RT(SBRT) and CT followed by surgical assessment. LAPC patients, received 6 to 8 cycles of chemotherapy and received SBRT at the discretion of treating physician. SBRT consisted of 42 -45 Gy over 5 fractions in 10 days.
Results
Between 2016-2020, 416 patients were treated. Of these 92(22.1%) staged as RPC ,153(36.7%) as BRPC and 171(41.1%) as LAPC. All the 92 RPC patients underwent upfront surgery. One third (28.1%) of the patients with BRPC either defaulted or progressed after NACT and 110(71.8%) patients were further evaluated. Post NACT,39(25.4%) patients with PR were surgically explored,32(20.9%) underwent R0/R1 resection and 71(46.4%) patients with SD not amenable for R0 resection received additional SBRT and CT. Of these, 29(18.9%) were surgically explored and 22(14.3%) underwent R0/R1 resection. Out of 171(41.1%) diagnosed with LAPC, 135 patients could receive 6 to 8 cycles of chemotherapy and 84 (49%) patients additionally received SBRT. Whereas 51 patients continued on CT.
RPC had a median follow up (MFU) of 19.5 months and the 2-year overall survival (OS) was 50.2% for these patients. In BRPC, at the MFU of 14 months the 2-year OS of these patients was 28.2% and the ones undergoing R0/R1 resection was 47%. Patients having R0 resection had a significantly superior OS (55.3% vs 27.3%(p=0.020) . The 2-year DFS in BRPC patients treated with neoadjuvant therapy (NAT) comprising NACT+/-SBRT, followed by surgery was comparable to RPC patients with upfront surgery (37.2% vs 49.2%, p value=0.033).
In LAPC patients at the MFU of 13 months, the median OS was 13 months. There was improved 2-year OS and DFS in patients receiving SBRT vs CT alone (p value=0.044 and 0.000 respectively).
Conclusion
Outcomes of BRPC patients who had resection post NAT were similar to the RPC patients treated with upfront surgery, proving the utility of NAT in BRPC patients. Addition of SBRT can further increase the resectability rate in BRPC patients not amenable for R0 resection. In unresectable LAPC, addition of SBRT significantly improved local control and survival outcomes compared to CT alone.