Department of Neurosurgery, Center of Pituitary Tumor, Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.
State Key Laboratory of Medical Genomics, Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.
Front Endocrinol (Lausanne). 2021 Mar 12;12:616339. doi: 10.3389/fendo.2021.616339. eCollection 2021.
Therapeutic agents for refractory prolactinomas that are resistant to dopamine agonists (DAs) are troublesome, and surgery often only removes a large part of the tumor without complete remission. Among the various second-line treatment regimens, the treatment effect of the alkylating agent temozolomide (TMZ) is only effective for approximately half of patients; however, complete remission is rare. Here we report a patient with prolactinoma who was resistant to high-dose cabergoline (CAB) treatment, demonstrating a continuous increase in both the tumor volume and the prolactin (PRL) level. Given that this case is a refractory prolactinoma, the patient underwent two transsphenoidal approach (TSA) surgeries. The pathological analysis indicated that the Ki-67 index increased significantly from 3% to 30%, and the expression levels of DRD2 and MGMT were low. Finally, TMZ treatment was recommended. A total of six cycles of TMZ standard chemotherapy shrank the tumor volume and the tumor disappeared completely. During the 6-month follow-up period, the tumor did not relapse again, and the PRL level was also normal. RNA sequencing and DNA whole genome sequencing were performed on this prolactinoma specimen, revealing 16 possible gene mutations, including a missense mutation of the PABPC1 gene. Additionally, the copy number variation analysis results showed that several chromosomes had copy number gains compared to the matched peripheral blood sample. In this case, low expression of DRD2 and high proliferation led to resistance to CAB, whereas low MGMT expression contributed to sensitivity to TMZ treatment. The results of genome sequencing still need further investigation at the molecular level to explain the tumor aggressiveness and high sensitivity to TMZ.
治疗对多巴胺激动剂（DAs）耐药的难治性泌乳素瘤的药物很棘手，手术通常只能切除大部分肿瘤，而无法完全缓解。在各种二线治疗方案中，烷化剂替莫唑胺（TMZ）的治疗效果仅对约一半的患者有效；然而，完全缓解的情况很少见。在这里，我们报告了一例对高剂量卡麦角林（CAB）治疗耐药的泌乳素瘤患者，其肿瘤体积和泌乳素（PRL）水平持续增加。鉴于该病例为难治性泌乳素瘤，患者接受了两次经蝶窦入路（TSA）手术。病理分析表明，Ki-67 指数从 3%显著增加至 30%，DRD2 和 MGMT 的表达水平较低。最终建议使用 TMZ 治疗。共进行了六个周期的 TMZ 标准化疗，肿瘤体积缩小，肿瘤完全消失。在 6 个月的随访期间，肿瘤没有再次复发，PRL 水平也恢复正常。对该泌乳素瘤标本进行了 RNA 测序和全基因组 DNA 测序，发现了 16 个可能的基因突变，包括 PABPC1 基因的错义突变。此外，拷贝数变异分析结果显示，与匹配的外周血样本相比，几条染色体的拷贝数增加。在这种情况下，DRD2 低表达和高增殖导致对 CAB 耐药，而 MGMT 低表达有助于对 TMZ 治疗敏感。基因组测序的结果仍需要进一步在分子水平上进行研究，以解释肿瘤的侵袭性和对 TMZ 的高敏感性。
