Carlos A. Torres‐Cabala

UNLABELLED: T cell-mediated immunotherapies are promising cancer treatments. However, most patients still fail to respond to these therapies. The molecular determinants of immune resistance are poorly understood. We show that loss of PTEN in tumor cells in preclinical models of melanoma inhibits T cell-mediated tumor killing and decreases T-cell trafficking into tumors. In patients, PTEN loss correlates with decreased T-cell infiltration at tumor sites, reduced likelihood of successful T-cell expansion from resected tumors, and inferior outcomes with PD-1 inhibitor therapy. PTEN loss in tumor cells increased the expression of immunosuppressive cytokines, resulting in decreased T-cell infiltration in tumors, and inhibited autophagy, which decreased T cell-mediated cell death. Treatment with a selective PI3Kβ inhibitor improved the efficacy of both anti-PD-1 and anti-CTLA-4 antibodies in murine models. Together, these findings demonstrate that PTEN loss promotes immune resistance and support the rationale to explore combinations of immunotherapies and PI3K-AKT pathway inhibitors. SIGNIFICANCE: This study adds to the growing evidence that oncogenic pathways in tumors can promote resistance to the antitumor immune response. As PTEN loss and PI3K-AKT pathway activation occur in multiple tumor types, the results support the rationale to further evaluate combinatorial strategies targeting the PI3K-AKT pathway to increase the efficacy of immunotherapy.

Hereditary leiomyomatosis and renal cell carcinoma (HLRCC) is an autosomal dominant familial syndrome characterized by the development of cutaneous and uterine leiomyomas as well as renal tumors. The mutation of this condition has been identified in the fumarate hydratase (FH, 1q42.3-q43) gene. The histology of the renal cancers has not been well described or illustrated because of the newness of the syndrome. We reviewed 40 renal tumors resected from 38 patients belonging to HLRCC families with proven fumarate hydratase germline mutation. Patients ranged in age from 17 to 75 years of age. Tumors were unilateral in all but 2 cases. The size of the tumors varied between 2.3 and 20 cm and there was no laterality preference. Several different architectural patterns were recognized: papillary (25 cases), tubulo-papillary (8 cases), tubular (2 cases), and solid (1 case). Mixed patterns were also present in 4 cases. The most important histologic feature of these neoplasms, which we believe to be the hallmark of the HLRCC tumors, is the presence of a characteristic large nucleus with a very prominent inclusion like orangiophilic or eosinophilic nucleolus, surrounded by a clear halo. Immunohistochemical studies did not provide a specific marker for these tumors, however, loss of heterozygosity at 1q32 and 1q42-44 was frequently found. These tumors are associated with poor prognosis and frequent spread to regional lymph nodes. At the moment, morphology is the best tool to recognize these tumors. Proper diagnosis of this syndrome by the pathologist may assist in early detection of these tumors.

Abstract Relatlimab and nivolumab combination immunotherapy improves progression-free survival over nivolumab monotherapy in patients with unresectable advanced melanoma 1 . We investigated this regimen in patients with resectable clinical stage III or oligometastatic stage IV melanoma (NCT02519322). Patients received two neoadjuvant doses (nivolumab 480 mg and relatlimab 160 mg intravenously every 4 weeks) followed by surgery, and then ten doses of adjuvant combination therapy. The primary end point was pathologic complete response (pCR) rate 2 . The combination resulted in 57% pCR rate and 70% overall pathologic response rate among 30 patients treated. The radiographic response rate using Response Evaluation Criteria in Solid Tumors 1.1 was 57%. No grade 3–4 immune-related adverse events were observed in the neoadjuvant setting. The 1- and 2-year recurrence-free survival rate was 100% and 92% for patients with any pathologic response, compared to 88% and 55% for patients who did not have a pathologic response ( P = 0.005). Increased immune cell infiltration at baseline, and decrease in M2 macrophages during treatment, were associated with pathologic response. Our results indicate that neoadjuvant relatlimab and nivolumab induces a high pCR rate. Safety during neoadjuvant therapy is favourable compared to other combination immunotherapy regimens. These data, in combination with the results of the RELATIVITY-047 trial 1 , provide further confirmation of the efficacy and safety of this new immunotherapy regimen.

PURPOSE: Herein we describe the evaluation and management of renal tumors in Birt-Hogg-Dubé (BHD), an autosomal dominant disorder predisposing to cutaneous fibrofolliculomas, pulmonary cysts, spontaneous pneumothorax and renal tumors. MATERIALS AND METHODS: A total of 124 affected individuals underwent comprehensive clinical evaluation, including body computerized tomography, to determine cutaneous, pulmonary and renal manifestations of BHD. Of these individuals 14 had their renal tumors managed at our institution. RESULTS: Of the 124 BHD affected individuals 34 (27%) had renal tumors of various histologies, most commonly hybrid oncocytic tumor and chromophobe renal carcinoma. Average age at renal tumor detection was 50.4 years and multiple tumors were found in a majority of patients. Some patients with renal tumors were identified that did not have the characteristic cutaneous hallmarks of BHD. In 4 of the 14 patients treated at our institution small (less than 3 cm) renal tumors were observed, while 10 others underwent a total of 12 renal procedures, including 4 radical and 8 partial nephrectomies. At a median of 38 months of followup 5 of these 10 patients remained free of disease, 3 had small renal tumors and 2 died of metastatic renal cancer. CONCLUSIONS: Patients with BHD are at risk for multiple renal tumors that are often malignant and can metastasize. Individuals at risk or affected by BHD should be radiographically screened for renal tumors at periodic intervals and they are best treated with nephron sparing surgical approaches. Genetic testing for this syndrome is now available.