Pembrolizumab-Induced Thyroiditis

Immune checkpoint inhibitors act to restore T cell-mediated antitumor immunity. By this nature, these cancer immunotherapy drugs are associated with various immune-related adverse events such as thyroid dysfunction. We describe a case of thyrotoxicosis secondary to a programmed cell death 1 (PD-1) immune checkpoint inhibitor, pembrolizumab. A 30-year-old female was started on pembrolizumab immunotherapy for stage III small cell carcinoma of the ovary, hypercalcemic type. Thirteen days after her second cycle of therapy, she presented with symptoms consistent with thyrotoxicosis. A thyroiditis was diagnosed by thyroid function tests and ultrasonography. She was originally treated with prednisone and metoprolol for possible Grave's disease. Pertechnetate thyroid scan was more consistent with thyroiditis secondary to pembrolizumab. She underwent a total thyroidectomy 10 days after initial presentation for refractory thyrotoxicosis despite maximal medical therapy. Her symptoms resolved and thyroid function tests significantly improved. Pathology was consistent with severe thyroiditis. Immune microenvironment may play a role in the expression of programmed cell death protein 1 ligand 1 (PD-L1). Chronic inflammation surrounding tumor upregulates PD-L1 expression on tumor cells by the release of cytokines, which acts to inhibit tumor destruction. We suggest that our patient had an undetected chronic inflammation of the thyroid, specifically Hashimoto's thyroidits, which predisposed her to thyroid destruction when taking pembrolizumab. Understanding that an inflammatory environment impacts thyroid toxicity to PD-1 inhibitor therapy is novel and should be further studied.

Genomic alterations in neuroendocrine cancers of the ovary

BACKGROUND

As we have previously reported, small cell carcinoma of the ovary (SCCO) is a rare, aggressive form of ovarian cancer associated with poor outcomes. In an effort to identify new treatment options, we utilized comprehensive genomic profiling to assess the potential for novel therapies in SCCO.

METHODS

Patients with SCCO, SCCO-HT (hypercalcemic type), neuroendocrine tumors of the ovary (NET-O), and small cell carcinoma of the lung (SCLC) profiled by Caris Life Sciences between 2007-2015 were identified. Tumors were assessed with up to 21 IHC stains, in situ hybridization of cMET, EGFR, HER2 and PIK3CA, and next-generation sequencing (NGS) as well as Sanger sequencing of selected genes.

RESULTS

Forty-six patients with SCCO (10 SCCO, 18 SCCO-HT, 18 NET-O) were identified as well as 58 patients with SCLC for comparison. Patients with SCCO and SCCO-HT were younger (median 42 years [range 12-75] and 26 years [range 8-40], respectively) than patients with NET-O 62 [range 13-76] or SCLC 66 [range 36-86]. SCCO patients were more likely to be metastatic (70 %) than SCCO-HT (50 %) or NET-O (33 %) patients, but at a similar rate to SCLC patients (65 %). PD1 expression varied across tumor type with SCCO (100 %), SCCO-HT (60 %), NET-O (33 %) vs SCLC (42 %). PDL1 expression also varied with SCCO (50 %), SCCO-HT (20 %), NET-O (33 %) and SCLC (0 %). No amplifications were identified in cMET, EGFR, or HER2 and only 1 was found in PIK3CA (NET-O). Actionable mutations were rare with 1 patient with SCCO having a BRCA2 mutation and 1 patient with NET-O having a PIK3CA mutation. No other actionable mutations were identified.

CONCLUSIONS

No recurrent actionable mutations or rearrangements were identified using this platform in SCCO. IHC patterns may help guide the use of chemotherapy in these rare tumors.

Small Cell Carcinoma of Ovary, Hypercalcemic Type: A Rare Case Report

BACKGROUND

Small cell carcinoma of the ovary, hypercalcemic type (SCCOHT), is a rare neoplasm that occurs mostly in women younger than 40 years of age. The unknown histogenesis makes the diagnosis of SCCOHT difficult. SCCOHT was recently shown to be associated with SMARCA4 gene mutation. Serum calcium levels can be used as a marker of treatment response and relapse in SCCOHT.

CASE REPORT

Here we report on a 16-year-old girl who presented with pelvic mass and hypercalcemia. SCCOHT was diagnosed histopathologically. However, loss of neither BRG1 nor INI1 expression was detected.

SUMMARY AND CONCLUSION

The diagnosis of SCCOHT should be among the differential diagnoses in adolescents presenting with pelvic mass and hypercalcemia. We would like to share our experience with this rare case, discuss recent management, and emphasize the importance of a multidisciplinary approach. Although it is known that almost all cases have a loss of BRG1 expression and a small group exhibit loss of INI1, our patient indicates that there could be exceptional cases with hitherto undescribed genetic abnormalities.