Chromophobe renal cell carcinoma (chRCC) is an uncommon kidney-cancer subtype with generally favorable outcomes in localized disease, although recurrence and sarcomatoid differentiation identify higher-risk groups. Published estimates place chRCC at roughly 3% to 10% of renal cell carcinomas, while reported survival varies with cohort design, follow-up, stage, and treatment.
Contents
- How common is chromophobe renal cell carcinoma?
- Age, sex, stage, and detection
- Survival and recurrence statistics
- Metastatic disease and sarcomatoid features
- Genomic and chromosomal findings
- Pathology and immunohistochemistry
How common is chromophobe renal cell carcinoma?
The reported share of chRCC depends on the population and the definition used. One genomic study described it as about 5% of renal cell carcinomas, while a clinicopathologic review reported 5% to 7%. Other publications gave estimates of 4% to 6% and 3% to 5%. A radiologic-pathologic review placed it at approximately 5% of adult kidney tumors. A large single-institution series reported a broader range of 5% to 10% of kidney cancers.
| Measure | Reported statistic | Source label |
|---|---|---|
| Share of renal cell carcinomas | About 5% | The somatic genomic landscape of chromophobe renal cell carcinoma |
| Share of renal cell carcinomas | 5%–7% | Chromophobe renal cell carcinoma: Novel molecular insights and clinicopathologic updates |
| Share of renal cell carcinomas | 4%–6% | Chromophobe renal cell cancer - review of the literature and potential methods of treating metastatic disease |
| Share of renal cell carcinomas | 3%–5% | Pathobiology and prognosis of chromophobe renal cell carcinoma |
| New U.S. cases per year | Roughly 3,000 | The somatic genomic landscape of chromophobe renal cell carcinoma |
The same radiologic-pathologic review identified chRCC as the third most common renal cell carcinoma subtype. The large single-institution series described it as the second most common non-clear-cell RCC form after papillary RCC. These rankings describe relative frequency among kidney-cancer subtypes, not a national incidence rate.
Age, sex, stage, and detection
Several clinical series show that chRCC is often found at an early stage, but the patient mix differs between studies. In a 50-case series, 53% of tumors were discovered incidentally and 86% were stage I. At last follow-up, 94% of patients were tumor-free or had died of causes unrelated to the tumor. The source label for these figures is Chromophobe Cell Renal Carcinoma: Clinicopathological Features of 50 Cases.
In a separate 53-case analysis, the mean age at diagnosis was 50.2 years, with an age range of 21 to 88 years. The male-to-female ratio was 1:1. Tumor stage was T1 in 75.5% of cases, T2 in 13.2%, and T3 in 11.3%. That study reported an overall survival rate of 100%. These are results from that specific 53-case series, not a universal survival expectation. The source label is Chromophobe renal cell carcinoma: analysis of 53 cases.
The larger multicenter European database series included 104 cases. Mean age at diagnosis was 57.6 years, with a range from 22 to 83 years. Diagnosis was incidental in 61.5% of cases, and the reported 5-year overall survival rate was 81%. The source label is Chromophobe renal cell carcinoma: comprehensive analysis of 104 cases from multicenter European database.
Survival and recurrence statistics
Long-term outcomes are favorable in several chRCC cohorts, particularly when the disease is localized. The Memorial Sloan Kettering series included 496 patients. Its 10-year recurrence-free survival rate was 91.7%, and its 10-year overall survival rate was 82.1%. In the same study, the comparator clear-cell RCC cohort had a 10-year recurrence-free survival rate of 79.4% and a 10-year overall survival rate of 63.6%. These figures are cohort comparisons, not direct predictions for an individual patient. The source label is Chromophobe Renal Cell Carcinoma: Results From a Large Single-Institution Series.
A nationwide nonmetastatic cohort included 683 patients, of whom 6.3% experienced recurrence. In a consecutive series of 295 patients, median follow-up was 58 months. Recurrence-free survival in that series was 94.3% at 5 years and 89.2% at 10 years. The source label for those figures is Understanding recurrence in chromophobe RCC.
Another review reported 5-year cancer-specific survival of 93% and 10-year cancer-specific survival of 87%. In that review, disease-specific recurrence, metastasis, or death was about 1.5% at 5 years and about 6.6% at 10 years. The source label is Chromophobe renal cell carcinoma: Novel molecular insights and clinicopathologic updates.
A SEER-based nomogram study reported separate results for training and validation cohorts after nephrectomy:
| Cohort | 5-year overall survival | 5-year cancer-specific survival |
|---|---|---|
| Training | 95.7% | 98.1% |
| Internal validation | 95.6% | 98.0% |
| External validation | 94.4% | 96.0% |
The source label for all six estimates is Nomograms for predicting overall and cancer-specific survival of patients with chromophobe renal cell carcinoma after nephrectomy. Training and validation results should be interpreted as study-model performance in their respective cohorts, rather than as interchangeable population estimates.
Metastatic disease and sarcomatoid features
Published estimates of metastatic incidence are also study-dependent. One review reported a metastatic incidence of 6% to 7%, while a genomic study of metastatic chRCC cited 5% to 10%. A tumor-vein invasion rate of about 5% was reported in Selected tumor markers in the routine diagnosis of chromophobe renal cell carcinoma.
The metastatic-genomics study analyzed 79 patients, including 38 with metastatic disease. In that study, chRCC typically showed about seven chromosome losses and about 31 exonic somatic mutations. The figures describe the analyzed tumors and should not be read as a rate of metastasis in all people with chRCC.
Sarcomatoid differentiation is an important adverse feature. It has been reported in approximately 8% of chRCCs. In a 14-case sarcomatoid series, mean tumor size was 14.6 cm, with a range of 9.5 to 28.0 cm. The mean sarcomatoid component was 67%, ranging from 30% to 99%. The source labels are Chromophobe Renal Cell Carcinoma with Sarcomatoid Differentiation: Clinicopathologic Correlation and Molecular Findings and Chromophobe renal cell carcinoma with sarcomatoid differentiation: a clinicopathologic study of 14 cases.
In a metastatic chRCC cohort, overall survival was 38.0 months without sarcomatoid features and 7.5 months with sarcomatoid features. Sarcomatoid features were associated with a hazard ratio of 4.7 for overall survival. The source label is Metastatic Chromophobe Renal Cell Carcinoma: Presence or Absence of Sarcomatoid Differentiation Determines Clinical Course and Treatment Outcomes.
Genomic and chromosomal findings
The somatic genomic landscape study profiled 66 chRCC tumors. The median exonic somatic mutation rate was about 0.4 mutations per megabase. TP53 was mutated in 32% of cases, PTEN in 9%, and mTOR-pathway targeting alterations were found in 23% of the 66 tumors. These are molecular findings in a profiled research cohort, not blood-test results or screening statistics.
Chromosomal losses are a recurring feature in reported genomic analyses. A comparative genomic hybridization study found underrepresentation of chromosome 1 in all 17 remaining tumors analyzed. Chromosomes 2, 10, and 13 were lost in 16 of 17 tumors; chromosomes 6 and 21 were lost in 15 of 17; and chromosome 17 was lost in 13 of 17. The source label is Specific loss of chromosomes 1, 2, 6, 10, 13, 17, and 21 in chromophobe renal cell carcinomas revealed by comparative genomic hybridization.
High-resolution DNA analysis confirmed monosomies of chromosomes 1, 2, 6, 10, 13, 17, and 21 in 70% to 93% of chRCCs. In the same analysis, chromosome 1 loss occurred in 24% of renal oncocytomas and chromosome 14 loss in 5% of renal oncocytomas. The source label is High-resolution DNA copy number and gene expression analyses distinguish chromophobe renal cell carcinomas and renal oncocytomas.
TCGA analysis confirmed characteristic losses of chromosomes 1, 2, 6, 10, 13, and 17 in 86% of tumors. Additional losses involving chromosomes 3, 5, 8, 9, 11, 18, and 21q were documented in 12% to 58% of tumors. The source labels are Chromophobe renal cell carcinoma: Novel molecular insights and clinicopathologic updates and Chromophobe renal cell carcinoma with Radiologic-Pathologic Correlation.
Pathology and immunohistochemistry
The reported mix of classic and eosinophilic morphology varies by cohort. Classic chromophobe tumors made up 76.2% of a Swiss cohort, 75.6% of a Japanese cohort, and 80.3% of the TCGA-KICH cohort in one comparative study. The source label is Classic Chromophobe Renal Cell Carcinoma Incur a Larger Number of Chromosomal Losses Than Seen in the Eosinophilic Subtype.
Immunohistochemical results also vary by study and sample size. In an 11-case study, CK7 was positive in 8 cases, or 73%; 1 case, or 9%, was focally positive; and 2 cases, or 18%, were negative. In a separate 45-case morphologic and immunohistochemical study, CK7 was positive in 100% of cases and CD117 was positive in 95.5%. The respective source labels are Cytokeratins 7 and 20 Immunoreactivity in Chromophobe Renal Cell Carcinomas and Renal Oncocytomas and Chromophobe renal cell carcinoma: A morphologic and immunohistochemical study of 45 cases.
In a differential-diagnosis study, EpCAM was expressed in all 22 chromophobe carcinomas in more than 90% of cells. A RET expression study found RET positivity in 4 of 10 chromophobe carcinomas, or 40%. The source labels are Immunohistochemical analysis of chromophobe renal cell carcinoma, renal oncocytoma, and clear cell carcinoma: an optimal and practical panel for differential diagnosis and RET protein expression in papillary renal cell carcinoma.
Together, these statistics show why chRCC estimates must be read with the study population, tumor stage, follow-up period, laboratory method, and source label in view. Percentages from small pathology series and molecular cohorts describe those sampled groups; they are not necessarily population-wide rates.