Metachronous primary cancer of the tongue and malignant lymphoma of the small intestine: A case report.

RATIONALE: Oral cancer often causes secondary primary cancers in the upper gastrointestinal tract. However, there are no reports of secondary primary cancers in patients with oral squamous cell carcinoma and malignant lymphoma of the small intestine. This report describes a case of metachronous multiple primary cancers of the tongue and small intestine malignant lymphoma. PATIENTS CONCERNS: The patient was admitted to our department with the chief complaint of pain in the right tongue. Partial tongue resection and supraomohyoid neck dissection were performed. One year after surgery, the patient experienced abdominal pain and bloody stools. DIAGNOSIS: Diffuse large B-cell lymphoma (DLBCL) was diagnosed via histological examination. INTERVENTIONS: A terminal ileum resection was performed. Postoperatively, the patient received 6 courses of rituximab, cyclophosphamide, doxorubicin hydrochloride, vincristine, and prednisone (R-CHOP). OUTCOMES: Five years after his initial diagnosis, there is no evidence of recurrence, metastasis, or other primary cancer. LESSONS: Oral cancer patients should always be followed up owing to a possibility of malignant tumors in other areas.

Novel humanized anti-CD20 antibody BM-ca binds to a unique epitope and exerts stronger cellular activity than others.

Cellular activity of BM-ca, a novel humanized anti-CD20 antibody, was quantitatively compared with that of two other anti-CD20 antibodies used for clinical practice, rituximab and ofatumumab. The results of a complement-dependent cytotoxicity (CDC) assay revealed that the strongest antibody was ofatumumab, followed by BM-ca, with rituximab being the weakest. Ofatumumab and BM-ca were effective not only against rituximab-sensitive SU-DHL-4 cells but also against rituximab-resistant RC-K8 cells. In an antibody-dependent cell-mediated cytotoxicity (ADCC) assay, although the effective concentrations against SU-DHL-4 cells were almost the same among these three antibodies, the maximum cytotoxic level was the highest for BM-ca. In an anti-cell proliferation assay using SU-DHL-4 cells, BM-ca was the most effective and ofatumumab, the weakest. Against RC-K8 cells, only BM-ca was effective. When combined with each of four cancer chemotherapeutics (prednisolone, vincristine, hydroxydaunorubicin, and cisplatin), BM-ca exerted the most effective combinatorial anti-cell proliferation activity. To assess the in vivo effect of BM-ca, we intravenously administered BM-ca into cynomolgus monkeys and found that the peripheral B-cell levels did not decrease in half of the animals. Sequencing of cDNA encoding CD20 of cynomolgus monkeys revealed that the responders and nonresponders had Leu/Pro (hetero) and Leu/Leu (homo) at amino acid (a.a.) position 160, respectively, suggesting that the epitope recognized by BM-ca was around this a.a. By analyzing reactivity to synthetic peptides, the epitope recognized by BM-ca was estimated to be a.a.'s 156-166, not shared with rituximab and ofatumumab. These results suggest BM-ca to be a promising anti-CD20 antibody having superior properties and recognizing a unique epitope.