Approach for reclassification of collecting duct carcinoma and comparative histopathological analysis with SMARCB1/INI1-deficient renal cell carcinoma and fumarate hydratase-deficient renal cell carcinoma

Collecting Duct Carcinoma: Characteristics and Survival Outcomes From UroCCR Database (CDCSurv UroCCR n°141)

OBJECTIVES

To describe characteristics and survival outcomes of patients with renal collecting duct carcinoma (RCDC).

METHODS

We retrospectively analyzed data from patients treated for RCDC and included in the UroCCR database between 2007 and 2023. All tumors had a centralized pathological review by a CARARE network pathologist. Oncologic outcomes for cancer-specific survival (CSS) and progression-free survival (PFS) were estimated using the Kaplan-Meier method.

RESULTS

A total of 29 patients with RCDC were included. The prevalence of RCDC in the UroCCR database was 0.18% (29/16133). The median age was 63 years (45-81). At diagnosis, 20 (69%) patients were symptomatic and 9 (31%) had a metastatic disease. Partial and radical nephrectomy were performed in respectively 8 (29.6%) and 19 (70.4%) cases. The median CSS were 21 months (95% CI 9.6-32) and median PFS was 7 months (95% CI 3.6-10.3). In the nonmetastatic group, the median CSS was 22 months (95% CI: 6.2-37), and median PFS was 12 months (95% CI: 0-39). Two years estimated PFS and CSS rates were respectively 29.7% and 38%. A localized disease (P = .012) and a tumor size inferior to 4 cm (P = .045) were associated with better oncological outcomes.

CONCLUSION

RCDC is a rare cancer with poor prognosis, and no treatment has demonstrated a significant improvement in survival. Recurrences are frequent and early. Management is heterogeneous and ineffective. These outcomes reinforce the need to better understand this tumor and evaluate alternative treatments.

SMARCB1-deficient poorly differentiated testicular carcinoma: a case report

In the present study, a 36-year-old male presented with left scrotal enlargement without an obvious cause, accompanied by a feeling of heaviness. Imaging examinations revealed a left testicular malignancy, the patient underwent left testicular mass removal,and the postoperative pathology results revealed a highly malignant germ cell tumor, with a tendency toward poorly differentiated embryonal carcinoma or seminoma. After surgery, the condition of the patient deteriorated rapidly, and distant tumor metastasis occurred. Lymph node puncture pathology results revealed poorly differentiated carcinoma consistent with SMARCB1/INI-1 deletion. Despite the use of chemotherapy, radiotherapy, immunotherapy and targeted therapy, the patient died 11 months after surgery. To the best of our knowledge, this is the first case report of a SMARCB1/INI1-deficient Poorly differentiated testicular carcinoma, which is very similar to testicular spermatocytic carcinoma in clinical diagnosis and deserves differentiation for future clinical diagnoses.This report provides important insights into the diagnosis and treatment of SMARCB1/INI1-deficient testicular malignancy. SMARCB1 is a crucial tumor suppressor gene, and its deficiency is closely associated with the development of various malignant tumors. The identification of this case suggests that future research should further explore the molecular mechanisms of SMARCB1-deficient tumors, particularly their role in testicular malignancies. Additionally, the diagnostic process of this case highlights that SMARCB1/INI1-deficient tumors can be clinically very similar to spermatocytic carcinoma of the testis, which can easily lead to misdiagnosis. Therefore, future clinical practice should emphasize the detection of SMARCB1/INI1 expression status, especially in the context of highly aggressive and rapidly progressing testicular malignancies, where immunohistochemical testing for SMARCB1/INI1 should be considered to confirm the diagnosis. In terms of treatment, this case demonstrates the highly aggressive nature and resistance to conventional therapies of SMARCB1/INI1-deficient tumors. Despite the patient receiving multiple treatments, disease progression could not be halted. This underscores the need for the development of novel therapeutic strategies targeting SMARCB1/INI1-deficient tumors, such as combinations of immune checkpoint inhibitors and targeted therapies, or other emerging immunotherapeutic approaches. Moreover, the treatment course of this patient also reflects the importance of individualized treatment plans. Future research should further explore precision medicine strategies based on tumor genetic profiles to improve patient survival rates and quality of life.

Fumarate hydratase-deficient renal cell carcinoma: a single institution-based study of 29 patients by clinicopathological, immunohistochemical and genetic approaches

Fumarate hydratase (FH)-deficient renal cell carcinoma (RCC) is a renal neoplasm associated with FH loss, aggressive behaviour, and poor survival. We present a histopathological and immunohistochemical overview of FH-deficient RCC to infer significant features for its differential diagnosis. In this study, FH-deficient RCC tissue samples from patients who underwent surgical resection or biopsy at a single institution between July 1995 and August 2022 were reviewed by conventional haematoxylin and eosin staining, immunohistochemistry, and whole genome analyses. Twenty-nine FH-deficient RCC specimens were examined ​based on immunohistochemistry findings regarding FH and S-(2-succino)cysteine (2SC). The histopathological findings included conspicuous nucleoli with a perinucleolar halo, resembling viral inclusion, eosinophilic cytoplasm, papillary and tubular growth patterns, and lack of stromal foam cell collection. Some tumours showed desmoplastic stroma, tumour-infiltrating lymphocytes, and solid growth pattern. One tumour presented low-grade oncocytic-like histomorphology. Widespread negativity for CD10, keratin 7, keratin 20, anaplastic lymphoma kinase, and GATA3 were observed in 24 specimens. All samples were positive for paired box gene 8, and the level of alpha-methylacyl-CoA racemase expression was variable. Whole exome sequencing of 19 tumours revealed nonsynonymous mutations, including missense mutations, splice donors, splice acceptors, frameshifts, and deletions in 15 tumours. Eleven tumours showed novel mutations. In conclusion, results revealed generally unfavourable clinical presentations and outcomes with a diverse range of FH mutations. These findings, along with the histopathological and immunohistochemical features, can be used to guide diagnosis and treatment.

SMARCB1-deficient renal medullary carcinoma with an EML4::ALK fusion gene in a Japanese woman

Renal medullary carcinoma is a rare, high-grade carcinoma arising in the renal medulla, which is usually associated with sickle cell trait, and there are very few documented cases in the Japanese population. We report a case of renal medullary carcinoma, immunohistochemically defined as SMARCB1 deficient, in a 67-year-old Japanese woman without a history of sickle cell trait. Somatic mutation of SMARCB1 and an EML4::ALK fusion gene were identified by comprehensive genomic profiling. Computed tomography revealed metastatic lesions in the retrocaval lymph nodes, liver, and bronchus. Six cycles of the dose-dense methotrexate, vinblastine, adriamycin, and cisplatin-combined chemotherapy were completed after an ultrasound-guided percutaneous biopsy of the renal tumor. After chemotherapy, the size of the original tumor in the right kidney had decreased in size, as well as the other metastatic lesions.

Genomic profiling and molecular characterization of non-clear cell renal cell carcinoma: a narrative review from a clinical perspective

While the clear-cell renal cell carcinoma (ccRCC) treatment has undergone several paradigm shifts in recent years, the non-clear cell renal cell carcinoma (nccRCC) therapeutic approach has yet to be extensively investigated and improved. The WHO 2022 classification of renal neoplasms redefined the most common nccRCC subtypes (papillary and chromophobe RCC) and introduced the molecularly defined RCC class, which is a first step in the direction of better molecular profiling of nccRCC. We reviewed the literature data on known genomic alterations of clinical interest in nccRCC and discussed their potential role in guiding therapeutic choices in each nccRCC entity. Among the alterations discussed, we focused on the ones that could be treated with already available drugs, such as MET-driven papillary RCC, mechanistic target of rapamycin altered chromophobe RCC, anaplastic lymphoma kinase-rearranged RCC, and fumarate-hydratase deficient RCC. Furthermore, we focused on the currently ongoing clinical trials and further evidence for all the other entities, such as SMARCB1-deficient RCC, TFE3 and transcription factorEB (TFEB)-altered RCC, and Elongin C (ELOC)-mutated RCC. The vast heterogeneity of nccRCC does not allow a one-size-fits-all solution; therefore, molecular characterization is the path toward effective therapies and fully personalized medicine for these entities.

Comparative analyses of tumour immune microenvironment between collecting duct carcinoma and fumarate hydratase-deficient renal cell carcinoma

AIMS

Collecting duct carcinoma (CDC) and fumarate hydratase-deficient renal cell carcinoma (FH-deficient RCC) have similar histological morphologies and both show a poor prognosis. Programmed death ligand 1 (PD-L1) inhibitor has been approved for the treatment of RCC. However, tumour-infiltrating neutrophils stimulated by interleukin-8 (IL-8) interfere with PD-L1 inhibitors. Here, we retrospectively analysed PD-L1 and IL-8 expression, and examined its relationship with infiltrating immune cells.

METHODS

Nine cases of CDC and seven cases of FH-deficient RCC were selected. We defined PD-L1 and IL-8 expression by the Tumour Proportion Score and Combined Positive Score (CPS). We counted the numbers of CD8+, CXCR2+, CD11b+, CD66b+ and CD33+ immune cells located in the tumour components.

RESULTS

A number of CXCR2+ (p=0.0058), CD11b+ (p=0.0070) and CD66b+ (p=0.0067) immune cells infiltrating into CDC were significantly higher than those infiltrating into FH-deficient RCC. In CDC, PD-L1 expression was correlated with a high density of CD8+ lymphocytes (p=0.0389), but was not in FH-deficient RCC (p=0.6985). IL-8 CPS was significantly higher in CDC than in FH-deficient RCC (p=0.0069). In addition, among the CDC cases, IL-8 CPS showed significant positive correlations with CXCR2+, CD11b+ and CD66b+ immune cell densities (p=0.0250, p=0.0104 and p=0.0374, respectively), whereas FH-deficient RCC showed no significant correlations between IL-8 CPS and immune cell densities.

CONCLUSIONS

Our results suggest the difference of each tumour microenvironment between CDC and FH-deficient RCC, and IL-8 is a potential therapeutic target for treating CDC, but not FH-deficient RCC.

Underreporting of SMARCB1 alteration by clinical sequencing: Integrative patho-genomic analysis captured SMARCB1/INI-1 deficiency in a vulvar yolk sac tumor

•SMARCB1/INI1-deficient gynecologic tumors are rare and clinically aggressive. A subset shows primitive yolk sac tumor features.•Due to technical limitation of next generation sequencing (NGS) and interlaboratory variability in sequencing methodologies and analytical pipelines, SMARCB1 deficiency caused by somatic copy number variations (SCNV) may be underreported by NGS.•To improve identification of SMARCB1/INI1-deficient neoplasm, we propose the following strategy: First, careful pathology slide review and detection of rhabdoid cells should raise the possibility of SMARCB1/INI1 deficiency. Second, INI1 IHC is a useful complementary test to exclude clinical suspicion of SMARCB1 deficiency in the context of negative molecular reporting. Third, knowledge of potential underreporting of SMARCB1 mutation would avoid underdiagnosis.