Mantle Cell Lymphoma: Incidence of Gastrointestinal Involvement and Correlation with Overall Response- Retrospective Review of Multiple Multicenter Trials
Authors: Bajpai Surabhi , Narang Jayant , Narang Shweta , Mankala Ravikanth , Jarecha Rudresh Rajnikant , Sharma Manish 
Published: November 2020

Background:Mantle cell lymphoma (MCL) is a rare kind of Non-Hodgkin Lymphoma. The incidence of Gastrointestinal (GI) involvement is an important factor in assessing patients and determining the disease burden, although it has not been studied extensively. It is relatively difficult to detect GI involvement by endoscopy especially for the small bowel however more frequent use of Positron Emission Tomography- Computed Tomography (PET-CT) has improved detection rates. GI involvement has an important role in staging and overall assessment. With this background we hypothesized that the patients with GI involvement will have a poorer Overall Response Rate (ORR) and sustained response as compared to patients without GI involvement.
Methods:A total of 120 patients were included in this retrospective analysis of multiple, phase II, clinical trials with MCL. These patients were independently reviewed using Lugano criteria. Patients with GI involvement at baseline and their subsequent response at Follow up were assessed. The Overall response rate (patients who achieved at least a CR or PR) and the sustained responses (of at least 6 months) of patients with GI involvement were compared with patients without GI involvement in this analysis. The subset of anatomical location of GI involvement was also assessed.
Results:
Out of a total of 120 patients, 34 had GI involvement noted on imaging. Correlative endoscopy findings were noted in 14 patients whereas in 20 patients endoscopy was not performed. The anatomical distribution of the gastrointestinal involvement on imaging was noted as follows: 17 Colon, 11 Small intestine (2 in Duodenum, 9 ileum), 11 Gastric, 1 Esophagus. Some patients had multifocal GI involvement.
In patients with GI involvement (n=34), CR was noted in 13 patients (sustained response in 11) while PR was documented in 11 patients (sustained response in 5).
In patients without the GI involvement (n=86) CR was noted in 39 patients (sustained response in 31) while PR was documented in 27 patients (sustained response in 16).
Conclusion:
Based on the results above it was observed that GI involvement was noted in approximately 28.3% of patients. Colon was the most common site involved, in 50% patients. Small Intestine and Gastric involvement were the next most common, 32% each. The incidence of GI involvement highlights the importance of predefining the imaging guidelines with the use of oral contrast to improve the detection of GI involvement. Any MCL patient with GI symptoms and suspected bowel involvement on imaging should always be followed up via endoscopy and biopsy when feasible to confirm the lymphomatous bowel involvement.
The ORR in cases with GI involvement was 70.5% (24/34) and out of these only 47% (16/34) patients showed sustained response. Patients without GI involvement was 76.7% (66/86) and out of these only 54% (47/86) patients showed sustained response. Our analysis suggests that the GI involvement in MCL patients have slightly less ORR as well as sustained response. Further prospective studies with larger number of patients may be needed to substantiate this claim, if GI involvement has poorer prognosis.

Disclosures
No relevant conflicts of interest to declare.