Background: Current staging systems for gallbladder cancer (GBC) are primarily based on surgical pathology and therefore are not relevant for unresectable patients and those undergoing neoadjuvant chemotherapy. Methods: Patients with a confirmed diagnosis of GBC managed at a tertiary referral center (2000–2016) were included. Independent predictors of overall survival (OS) were identified using multivariable analysis (MVA). A combination of these variables was then assessed to identify a set of factors that provided maximal accuracy in predicting OS, and a nomogram and a new staging system were created based on these factors. Harrell’s C-statistic was calculated to evaluate the predictive accuracy of the nomogram and staging system. Results: A total of 528 patients were included in the final analysis. On MVA, factors predictive of poor OS were older age, ECOG performance status, hemoglobin level <9 g/dL, presence of metastases, and alkaline phosphatase (ALP) level >200 U/L. A nomogram and a 4-tier staging system predictive of OS were created using age at diagnosis, ECOG status, tumor size, presence or absence of metastasis, and ALP level. The C-statistic for this novel staging system was 0.71 compared with 0.69 for the TNM staging system (P=.08). In patients who did not undergo surgery, the C-statistics of the novel and TNM staging systems were 0.60 and 0.51, respectively (P<.001). Conclusions: We created a novel, clinically based staging system for GBC based on nonoperative information at the time of diagnosis that was superior to the TNM staging system in predicting OS in patients who did not undergo surgery, and that performed on par with TNM staging in surgical patients.
Siddhartha Yadav, Sri Harsha Tella, Anuhya Kommalapati, Kristin Mara, Kritika Prasai, Mohamed Hamdy Mady, Mohamed Hassan, Rory L. Smoot, Sean P. Cleary, Mark J. Truty, Lewis R. Roberts, and Amit Mahipal
Amro M. Abdelrahman, Ajit H. Goenka, Roberto Alva-Ruiz, Jennifer A. Yonkus, Jennifer L. Leiting, Rondell P. Graham, Kenneth W. Merrell, Cornelius A. Thiels, Christopher L. Hallemeier, Susanne G. Warner, Michael G. Haddock, Travis E. Grotz, Nguyen H. Tran, Rory L. Smoot, Wen Wee Ma, Sean P. Cleary, Robert R. McWilliams, David M. Nagorney, Thorvardur R. Halfdanarson, Michael L. Kendrick, and Mark J. Truty
Background: Neoadjuvant therapy (NAT) is used in borderline resectable/locally advanced (BR/LA) pancreatic ductal adenocarcinoma (PDAC). Anatomic imaging (CT/MRI) poorly predicts response, and biochemical (CA 19-9) markers are not useful (nonsecretors/nonelevated) in many patients. Pathologic response highly predicts survival post-NAT, but is only known postoperatively. Because metabolic imaging (FDG-PET) reveals primary tumor viability, this study aimed to evaluate our experience with preoperative FDG-PET in patients with BR/LA PDAC in predicting NAT response and survival. Methods: We reviewed all patients with resected BR/LA PDAC who underwent NAT with FDG-PET within 60 days of resection. Pre- and post-NAT metabolic (FDG-PET) and biochemical (CA 19-9) responses were dichotomized in addition to pathologic responses. We compared post-NAT metabolic and biochemical responses as preoperative predictors of pathologic responses and recurrence-free survival (RFS) and overall survival (OS). Results: We identified 202 eligible patients. Post-NAT, 58% of patients had optimization of CA 19-9 levels. Major metabolic and pathologic responses were present in 51% and 38% of patients, respectively. Median RFS and OS times were 21 and 48.7 months, respectively. Metabolic response was superior to biochemical response in predicting pathologic response (area under the curve, 0.86 vs 0.75; P<.001). Metabolic response was the only univariate preoperative predictor of OS (odds ratio, 0.25; 95% CI, 0.13–0.40), and was highly correlated (P=.001) with pathologic response as opposed to biochemical response alone. After multivariate adjustment, metabolic response was the single largest independent preoperative predictor (P<.001) for pathologic response (odds ratio, 43.2; 95% CI, 16.9–153.2), RFS (hazard ratio, 0.37; 95% CI, 0.2–0.6), and OS (hazard ratio, 0.21; 95% CI, 0.1–0.4). Conclusions: Among patients with post-NAT resected BR/LA PDAC, FDG-PET highly predicts pathologic response and survival, superior to biochemical responses alone. Given the poor ability of anatomic imaging or biochemical markers to assess NAT responses in these patients, FDG-PET is a preoperative metric of NAT efficacy, thereby allowing potential therapeutic alterations and surgical treatment decisions. We suggest that FDG-PET should be an adjunct and recommended modality during the NAT phase of care for these patients.