Thymic epithelial tumors and metastasis to the brain: a case series and systematic review

A Rare Case of Neck Sarcomatoid Squamous Cell Carcinoma With Brain Metastases

Squamous cell carcinoma (SCC) is the second most prominent form of skin malignancy. It occurs most frequently in older males with fair skin complexion that have extensive sun exposure most commonly in their childhood. The metastatic presentation of SCC is rare and is most common in the lung. In this paper, we present the unique case of a 73-year-old patient with sarcomatoid squamous cell carcinoma in their posterior neck that metastasized to the brain.

Central Nervous System Metastases in Thymic Epithelial Tumors: A Brief Report of Real-World Insight From RYTHMIC

Thymic epithelial tumors (TETs) are rare malignancies ranging from indolent thymoma A to aggressive thymic carcinomas (TCs). Brain metastases are extremely infrequent for TETs and have only been described in case reports or small single-center series. RYTHMIC (Réseau tumeurs THYMiques et Cancer) is a French nationwide network mandated to systematically review every TET case and prospectively includes all consecutive patients discussed by national or regional tumor boards. We analyzed patients with TETs and central nervous system (CNS) metastasis during their cancer history from this large French registry. In an 8-year period, 2909 patients were included in the database, including 248 TCs (8.5%). A total of 14 patients had CNS metastases, five (36%) at diagnosis and nine (64%) at relapse. Among them, 12 patients (86%) had a diagnosis of TC and two (14%) had thymoma A and B3. Surgical biopsies were performed, and the histologic subtype for non-TC tumors was centrally confirmed. Median overall survival was 22 months (95% confidence interval [CI]: 9.8-34.2), with longer, albeit not significant, overall survival when CNS metastases were present at diagnosis versus relapse (not reached versus 17 mo; p = 0.29); median progression-free survival was 13 versus 8 months (p = 0.06), respectively. A higher risk of death (hazard ratio = 5.34, 95% CI: 1.3-21.9, p = 0.02) and relapse (hazard ratio = 1.89, 95% CI: 0.9-3.7, p = 0.06) was observed for patients suffering from TC with brain metastases compared with those without CNS extension. CNS disease was extremely rare in our TET cohort (0.48%), reported at both diagnosis and progression, present primarily in TC, with prevalence rising to 4.9%.

The role of drug efflux and uptake transporters ABCB1 (P-gp), ABCG2 (BCRP) and OATP1A/1B and of CYP3A4 in the pharmacokinetics of the CDK inhibitor milciclib

The promising anticancer drug milciclib potently inhibits cyclin-dependent kinase (CDK) 2 and tropomyosin receptor kinase (TRK) A, and is currently in phase II clinical studies. To characterize factors affecting milciclib pharmacokinetics, we investigated whether milciclib is a substrate of the multidrug efflux and uptake transporters ABCB1 (P-gp), ABCG2 (BCRP), and OATP1A/1B, and the drug-metabolizing enzyme CYP3A, using genetically-modified mouse models and Madin-Darby Canine Kidney (MDCK-II) cells. In vitro, milciclib was transported by mAbcg2, and this was inhibited by the ABCG2 inhibitor Ko143. Upon oral administration of milciclib, its plasma exposure in Abcb1a/1b^-/-, Abcg2^-/-, and Abcb1a/1b;Abcg2^-/- mice was similar to that found in wild-type mice. Milciclib showed good brain penetration even in wild-type mice (brain-to-plasma ratio of 1.2), but this was further increased by 5.2-fold when both Abcb1 and Abcg2 were ablated, and to a lesser extent in single Abcb1- or Abcg2-deficient mice. Oatp1a/1b deficiency had only a minor impact on the milciclib plasma AUC_0-24h and C_max. The milciclib AUC_0-8h increased 1.9-fold in Cyp3a^-/- mice but decreased only 1.3-fold upon overexpression of human CYP3A4. Thus, ABCB1 and ABCG2 cooperatively limit milciclib brain penetration. The low impact of OATP1 and CYP3A could be clinically favorable for milciclib, reducing the risks of unintended drug-drug interactions or interindividual variation in CYP3A4 activity.

Laparoscopic dissection for pelvic lymph node recurrence of thymic carcinoma: A case report

Thymic carcinoma, a rare mediastinal neoplasm, is characterized by extensive local invasion and distant metastasis. To our knowledge, this is the first case report demonstrating the efficacy of laparoscopic dissection for pelvic lymph node metastases from thymic carcinoma. A 64-year-old man was found to have a mediastinal mass by CT and underwent radical resection. Six months after resection of his thymic carcinoma, follow-up CT revealed a gluteal tumor and enlarged pelvic lymph nodes. The gluteal tumor was resected percutaneously. Two months after this procedure, PET showed that the three pelvic lymph nodes had abnormal uptake of ¹⁸ F-fluorodeoxyglucose and had enlarged further. The patient accordingly underwent laparoscopic dissection of these lymph nodes. Pathological examination of all resected specimens showed metastatic thymic carcinoma. We recommend laparoscopic dissection of pelvic lymph node metastases because it provides a clear intraoperative view and is minimally invasive.