Clinical Outcomes in Patients With Metastatic Papillary Renal-Cell Carcinoma: A Multi-Institutional Study in Japan

Long-term disease control of metastatic type 2 papillary renal cell carcinoma using local treatment and molecular targeted therapy: A case report

A 46-year-old man underwent right partial nephrectomy for type 2 papillary renal cell carcinoma (PRCC) in 2011. Lung metastasis and lymph node (LN) metastases around the inferior vena cave appeared in 2012. A right radical nephrectomy and extensive LN dissection was performed and the resection of lung metastasis was performed one month after the nephrectomy. Mediastinal LN metastases occurred in 2013, and resection of the affected LNs was performed. Sunitinib and zoledronic acid was started in 2014 because mediastinal LN swelling and multiple bone metastases appeared. Sunitinib treatment was stopped soon after due to adverse events and axitinib treatment was started. Axitinib was effective and the patient had stable disease for 30 months. Adverse events were successfully controlled by dose reduction and periodic drug withdrawal schedules (for example, 5 days on, 2 days off). Axitinib was further continued for 19 months as the metastatic lesions had progressed slowly. Temsirolimus treatment was started in 2019, but it was stopped after three cycles due to interstitial pneumonia. The patient died 80 months after the initial recurrence. Using multidisciplinary treatment, durable disease control was achieved in a patient with metastatic type 2 PRCC.

Difficulty in differential diagnosis for renal cancer with microscopic papillary architecture: overlapped pathological features among papillary renal cell carcinoma (RCC), mutinous tubular and spindle cell carcinoma, and unclassified RCC. Lessons from a Japanese multicenter study

OBJECTIVES

In our multicenter study evaluating metastatic papillary renal cell carcinoma (PRCC), 29% of tumors diagnosed as PRCC in collaborative institutes were finally diagnosed as other RCCs under central review. In those tumors, mucinous tubular and spindle cell carcinoma (MTSCC) was the leading histology, followed by unclassified RCC (ucRCC). We focused on those patients with MTSCC or ucRCC.

METHODS

We reviewed the processes for the pathological diagnoses of nine tumors and reviewed their clinical features.

RESULTS

All of the MTSCCs and ucRCCs were positive for AMACR, which is frequently positive in PRCC. Mucin was demonstrated in 80% of the MTSCCs, and its presence is important for their diagnoses. One MTSCC was diagnosed as a mucin-poor variant. The presence of spindle cells with low-grade nuclei was suggestive of MTSCC, but the diagnosis of high-grade MTSCC was difficult. Four tumors were diagnosed as ucRCC by histological and immunohistochemical findings. Three of the four tumors were suspicious of ucRCC in the initial review due to atypical findings as PRCC. Sunitinib and interferon-α were effective for one MTSCC patient who survived for >5 years. Two MTSCC patients who were Memorial Sloan-Kettering Cancer Center poor risk had unfavorable prognoses. One patient with mucin-poor MTSCC had an indolent clinical course. Two of four ucRCC patients showed durable stable disease with targeted agents (TAs) and survived >3 years.

CONCLUSION

Some MTSCC metastases progressed very slowly and poor-risk tumors progressed rapidly. Systemic therapies including TAs showed some efficacies. Some patients who have metastatic ucRCC with microscopic papillary architecture can benefit from TAs.

Sex-specific analysis of renal cell carcinoma histology and survival in Japan: A population-based study 2004 to 2016

Background and aims

In Western countries, sex differences in renal cell carcinoma (RCC) histology and survival have been previously described: compared with men, clear cell subtype is more common but overall prognosis is better among women. The goal of the present study was to examine sex differences in RCC histology and survival in Japan, using a large-scale population-based data set.

Methods

With the use of a population-based cancer registry in Japan (2004-2016), patients with primary RCC were followed for 5 years (median follow-up time 2.1 years). We distinguished histological subtypes of clear cell, papillary, and chromophobe from "others" subtype. Sex-specific prevalence ratio (PR) for each histological subtype was estimated by Poisson regression with robust variance, adjusted for age and year of diagnosis. Sex-specific survival rates were estimated by Cox proportional hazard regression, adjusted for age, year of diagnosis, histological subtypes, and other prognostic variables, with multiple imputation.

Results

The prevalence of clear cell and "others" subtypes was similar between men and women among all the 5265 study subjects during the 12 years of study (clear cell, male 88.6% vs female 87.1%; "others", male 5.3% vs female 5.3%). However, papillary subtype was less common among women than men (male 4.6% vs female 2.8%; PR = 0.63; 95% CI, 0.45-0.88), while chromophobe subtype was more common among women (male 1.6% vs female 4.8%; PR = 3.18; 95% CI, 2.26-4.47). Although "others" subtype (but not papillary/chromophobe subtypes) independently predicted prognosis (HR = 1.74; 95% CI, 1.32-2.30), no sex differences were observed in RCC survival.

Conclusion

We did not observe a statistically significant difference in the prevalence of clear cell subtype between men and women in Japan, which differs from the pattern previously described in Western countries. Sex differences in RCC histology may not affect RCC survival in this population.