Introduction
Pancreatic cancer is a challenging disease with an increasing incidence and extremely poor prognosis due to a late diagnosis, an early metastatic potential and a resistance to treatment. In addition to the traditional prognostic factors (tumor status, response to treatment), the identification of new prognostic factors seems to be essential for a better adaptation of the therapeutic management. In this context, radiological sarcopenia, a new emerging concept translating skeletal muscle loss, is a frequent situation in oncology and been identified as an independent factor of poor survival in gastrointestinal neoplasia. However, few studies have evaluated the prognostic impact of psoas muscle volume, an emerging alternative to skeletal mass index, as a marker of sarcopenia in pancreatic cancer.
Aims & Methods
This study aimed to investigate the relationship between pre-therapeutic sarcopenia evaluated by the total psoas area index (TPAI) and survival outcomes in pancreatic cancer. We conducted a retrospective, single-center study, including patients diagnosed with pancreatic adenocarcinoma between 2014 and 2022. We have excluded patients having computed tomography (CT) performed in others centers and not included in our database, patients with history of other neoplasia, cirrhosis, inflammatory bowel disease and intestinal resection. Measurement of the psoas muscle area has been applied to estimate lean muscle mass as a surrogate marker of sarcopenia. These measurements were performed CT by calculating the total psoas area at the third lumbar vertebra level. Then, TPAI was calculated using the equation: TPAI (mm2/m2) = (Left Psoas Area (mm²) + Right Psoas Area (mm²/)) / Height (m²). Sarcopenia was defined by a TPAI less than 414.5 mm²/m² for female patients and 564.2 mm²/m² for male patients.
Results
A total of 30 patients were enrolled (80 % male; mean age 61 ± 11 years). The pancreatic tumor was located in the head (66.6%), in the body (16,7%) and in the tail (16.7%). The tumor was resectable in 11 patients (36%), locally advanced in 10 patients (33%) and metastatic in 9 patients (9%). Regarding treatment, 33.3% of patients underwent surgery and 30% received palliative chemotherapy. The mean TPAI was 459,66 ± 216,47 mm²/m² (range 200 - 1120 mm²/m²). The overall incidence of sarcopenia according to TPAI was 66% (N = 20). The mean survival was 12 months. Recurrence-free survival rates at 6 months, 12 months and 36 months were 50%, 36.7% and 25% respectively. In univariate analysis, sarcopenia was significantly associted to lower albumin level (31.05 ± 5.57 vs 37.8 ± 4.84, p = 0.004). The sarcopenic patients were, on average, older than the nonsarcopenic patients, but without significant difference (62 ± 12 years vs 58 ± 11 years, p>0.05). Sarcopenia was not associated with diabetes mellitus, smoking, anemia, lymphopenia or CA 19-9 level.
In term of survival, the difference between the two Kaplan-Meier curves of sarcopenic versus non-sarcopenic patients was statistically significant (log rank test p=0.01), [HR = 2,95 (95% CI = 1 – 7)], with a mean survival period of 7.80 ± 9.57 versus 20.40 ± 4.84 months respectively (p=0.028). When analyzing the receiver operating characteristic (ROC) curve, AUC of TPAI in predicting 12 months survival was 0.871 (95% CI: 0.741–1, p=0.001).
Conclusion
The TPAI is a valuable marker of sarcopenia, easy to measure correlated with negative prognostic impact in patients with pancreatic cancer allowing better pre-therapeutic stratification.
References
Amini, N.; Spolverato, G.; Gupta, R.; Margonis, G.A.; Kim, Y.; Wagner, D. Impact Total Psoas Volume on Short- and Long-Term Outcomes in Patients Undergoing Curative Resection for Pancreatic Adenocarcinoma: A New Tool to Assess Sarcopenia. J. Gastrointest Surg. 2015, 19, 1593–1602