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Renal Cell Carcinoma

Chapter 90 | Part 4: Oncology and Hematology · Part 4 – Oncology: Solid Tumors · Chapter 90

Key Clinical Points

  1. Renal Cell Carcinoma (RCC) accounts for 90–95% of malignant neoplasms arising from the kidney.
  2. The classic triad of hematuria, flank pain, and a palpable abdominal mass is now rare due to earlier detection via imaging.
  3. Clear cell carcinoma is the predominant histology (70%), characterized by loss of chromosome 3p and VHL gene inactivation.
  4. Hereditary syndromes include von Hippel-Lindau (VHL), Hereditary Papillary RCC, Birt-Hogg-Dubé, and others.
  5. The IMDC risk model for metastatic RCC includes six factors: poor performance status, low hemoglobin, high serum calcium, high neutrophil levels, high platelet levels, and <1-year interval from diagnosis to treatment.
  6. Systemic therapy for metastatic RCC utilizes tyrosine kinase inhibitors (TKIs) targeting VEGF receptors and checkpoint inhibitors targeting PD-1/CTLA-4.
  7. Belzutifan is an approved oral inhibitor of HIF-2α specifically for VHL-associated cancers.
  8. Staging follows the AJCC TNM system; Stage I is ≤7 cm confined to the kidney, while Stage IV includes distant metastases.
  9. Paraneoplastic syndromes include erythrocytosis (~3%), hypercalcemia, Stauffer's syndrome (nonmetastatic hepatic dysfunction), and acquired dysfibrinogenemia.

1. DEFINITION & OVERVIEW

Renal Cell Carcinoma (RCC) is a heterogeneous group of tumors with distinct histopathologic, genetic, and clinical features.

• Prevalence: ◦ Accounts for 90–95% of malignant neoplasms arising from the kidney. ◦ The remaining 5–10% are typically transitional cell carcinomas (urothelial) originating in the renal pelvis.

• Clinical Characteristics: ◦ Often diagnosed without symptoms due to advanced imaging. ◦ Resistance to cytotoxic agents. ◦ Robust response to angiogenesis-targeted agents. ◦ Susceptibility to checkpoint-directed immunotherapy. ◦ Variable clinical course for patients with metastatic disease. ◦ Rare instances of spontaneous regression reported.

1.1 Histologic Classification

• Clear cell carcinoma: 70% of cases; arises from epithelial cells of the proximal tubules. • Papillary RCC: 10–15% of cases; can be bilateral and multifocal. • Chromophobe RCC: ≤5% of cases; typically has a more indolent clinical course. • TFE3-rearranged RCC: <5% of cases; rare in adults, but the predominant histology in children. • SMARCB1-deficient RCC: Rare, very aggressive; associated with sickle cell trait (formerly known as renal medullary carcinoma). • Unclassified: Tumors not meeting criteria for defined variants; variable clinical courses.

Table 90-2 summarizes these classifications based on growth patterns, chromosomal events, and specific gene alterations.

2. EPIDEMIOLOGY

• Incidence: ◦ Approximately 81,000 cases annually in the United States. • Mortality: Approximately 15,000 deaths per year. • Rank: ◦ 7th most common cancer overall in the US. ◦ 6th most common in males; 9th most common in females. • Demographics: ◦ Male-to-female ratio is 2:1. ◦ Rare in individuals under 45 years of age. ◦ Incidence peaks between ages 55 and 75. • Risk Factors: ◦ Associated with cigarette smoking, obesity, and hypertension. ◦ Increased risk in patients with polycystic kidney disease complicated by chronic renal failure.

3. ETIOLOGY & PATHOPHYSIOLOGY

• Sporadic vs. Hereditary: Most cases are sporadic; however, several well-established hereditary forms exist. • VHL Syndrome: ◦ Aut10ms dominant disorder involving the VHL gene on chromosome 3p25. ◦ 70% estimated lifetime risk of developing clear cell RCC. ◦ Associated findings: retinal hemangioma, hemangioblastoma (CNS), pheochromocytoma, and neuroendocrine tumors.

3.1 Hereditary Syndromes

Table 90-1 details the specific genetic profiles of hereditary renal tumors:

• von Hippel-Lindau syndrome: 3p25; VHL gene; Clear cell type. • Hereditary papillary RCC: 7p31; MET gene; Papillary type (bilateral/multifocal). • Hereditary leiomyomatosis and RCC (HLRCC): 1q42; FH gene; FH-deficient type; associated with leiomyoma. • Birt-Hogg-Dubé syndrome: 17p11; FLCN gene; Chromophobe, clear cell, or oncocytoma. • Tuberous sclerosis: 9q34 (TSC1), 16p13 (TSC2); Angiomyolipomas and various RCC types. • BAP1 tumor predisposition syndrome: 3p21; BAP1 gene; Mostly clear cell.

3.2 Molecular Pathogenesis

• Clear Cell Tumors: ◦ Found in >80% of patients with metastases. ◦ Arise from proximal tubule epithelial cells. ◦ Early event: Loss of chromosome 3p → loss of heterozygosity for VHL, PBRM1, BAP1, and SETD2. • VHL Function: ◦ Encodes a tumor-suppressor protein regulating VEGF transcription via ubiquitination of hypoxia-inducible factors (HIF). • Inactivation Effect: ◦ Inactivation → upregulation of VEGF signaling → promotes tumor angiogenesis and growth → susceptibility to antiangiogenesis therapy. • Metastatic Risk: Early loss of chromosome 9p correlates with high risk for early metastatic dissemination and poor survival. • Papillary Variants: Activating mutations in MET or gain of chromosome 7 (where MET is located) are hallmarks; actionable via targeted MET inhibitors. • Chromophobe Tumors: Originate from distal nephron; characterized by aneuploidy and loss of chromosomes 1, 2, 6, 10, 13, and 17.

4. CLINICAL FEATURES

• Presentation: ◦ Often asymptomatic; frequently discovered as incidental findings on imaging. • Symptoms: Hematuria, flank/abdominal pain, and a palpable mass. • Systemic Signs: Fever, weight loss, anemia, and varicocele.

Table 90-1 and the clinical text highlight specific paraneoplastic syndromes.

4.1 Classic Triad

• Components: Hematuria, flank pain, and a palpable abdominal mass. • Current Status: Rare due to earlier detection via imaging.

4.2 Paraneoplastic Syndromes

• Stauffer's syndrome: Nonmetastatic hepatic dysfunction. • Erythrocytosis: Noted in only about 3% of patients. • Hypercalcemia. • Acquired dysfibrinogenemia.

5. DIFFERENTIAL DIAGNOSIS

• Benign Lesions: Cysts, adenoma, angiomyolipoma, oncocytoma. • Inflammatory/Infectious: Pyelonephritis or abscesses. • Other Malignancies: ◦ Transitional cell carcinoma (renal pelvis) ◦ Sarcoma ◦ Lymphoma ◦ Wilms' tumor • Metastases: From other primary sites. • Note: RCC is the most common cause of renal masses among these options.

6. INVESTIGATIONS & DIAGNOSIS

  1. Initial Evaluation: • CT scan of abdomen and pelvis • Chest radiograph • Urine analysis
  2. Metastatic Workup: • If chest radiograph suggests metastasis → perform CT of the chest.
  3. Advanced Imaging: • MRI: Used for evaluating inferior vena cava (IVC) involvement/thrombus or when IV contrast is contraindicated due to renal function.
  4. Management Decisions based on Findings: • General Rule: Any solid renal mass should be considered malignant until proven otherwise. • No Metastases: Surgery is indicated, even if the renal vein or IVC is involved. • Small Tumors (especially clear cell): → Lower risk of impending metastatic spread → biopsy may be performed to confirm histology → radiographic surveillance until surgery.

6.1 Staging System

Staging is based on the AJCC TNM system.

• T Stage (Tumor): ◦ T1: ≤7 cm in greatest diameter. ◦ T2: >7 cm and confined to the kidney. ◦ T3: Extends through renal capsule but remains within Gerota's fascia; includes involvement of major veins or perinephric tissues. ◦ T4: Extension beyond Gerota's fascia, including contiguous extensions or into the ipsilateral adrenal gland.

• N Stage (Regional Lymph Nodes): ◦ N0: No regional lymph node involvement. ◦ N1: Regional lymph node involvement.

• M Stage (Distant Metastasis): ◦ M0: No distant metastases. ◦ M1: Distant metastases, including nonregional lymph nodes.

• Anatomic Staging: ◦ Stage I: T1, N0, M0 ◦ Stage II: T2, N0, M0 ◦ Stage III: T3, N0 or N1, M0 ◦ Stage IV: T4, any N, M1

• Prevalence & Prognosis: ◦ 65% of patients present with stage I or II. ◦ 15–20% present with stage III. ◦ 15–20% present with stage IV. ◦ 5-year survival rate is currently 77% across all RCCs.

7. MANAGEMENT & TREATMENT

  1. Localized Disease (Stage I, II, and selected III): • Primary treatment: Radical or partial nephrectomy. • Radical Nephrectomy: En bloc removal of Gerota's fascia, kidney, and potentially ipsilateral adrenal gland/lymph nodes. • Partial Nephrectomy (Nephron-sparing): Appropriate for small tumors, solitary kidneys, bilateral tumors, or patients with compromised renal function. • Note: Venous involvement (Stage III) does not preclude surgical resection; this includes thrombectomy.

  2. Metastatic Disease: • Primary treatment: Systemic therapy. • Strategy: Treatment may be continued with noncurative intent until progression is documented on cross-sectional imaging.

  3. Systemic Therapy Agents: • Tyrosine Kinase Inhibitors (TKIs): Target VEGF receptors. • Checkpoint Inhibitors: Target PD-1 or CTLA-4.

  4. Specialized Targeted Therapy: • Belzutifan: Oral inhibitor of HIF-2α; specifically approved for VHL-associated cancers.

Localized Disease Management

• Surgery Selection: → Small tumors / Solitary kidney / Bilateral tumors → Partial nephrectomy. → Large tumors / Standard cases → Radical nephrectomy. • Note: Radical nephrectomy involves removal of Gerota's fascia and its contents.

Metastatic Disease Management

• Treatment Strategy: → Systemic therapy (TKIs or Checkpoint Inhibitors) is the mainstay. → Treatment continues until progression on imaging.

COMPLICATIONS & PROGNOSIS

• Overall Survival: 77% across all RCCs (varies by stage). • IMDC Risk Model (6 factors for metastatic disease): 1. Poor performance status 2. Low hemoglobin concentration 3. High serum calcium 4. High neutrophil levels 5. High platelet levels 6. <1-year interval from diagnosis to systemic treatment. • Metastatic Sites: Most common are lungs, lymph nodes, liver, bone, and brain.

SPECIAL POPULATIONS

• Nephron-Sparing Surgery: Indicated for patients with solitary kidneys, bilateral tumors, or chronic renal insufficiency. • Palliation: Radiation therapy (e.g., external-beam, stereotactic radiosurgery) used specifically for bone or brain metastases.

KEY PEARLS & HIGH-YIELD POINTS

• Internist's Tumor: Historically named so because it was often discovered via paraneoplastic syndromes. • Triad Rarity: Hematuria, flank pain, and palpable mass are now rare due to imaging detection. • Erythrocytosis: Only present in ~3% of patients at presentation. • VHL Syndrome: 70% risk of clear cell RCC; targeted by Belzutifan (HIF-2α inhibitor). • Unclassified Tumors: Any tumor not meeting specific criteria for defined variants.

Reference Tables

TABLE 90-1 Hereditary Renal Cell Tumors SYNDROME von Hippel-Lindau syndrome

Harrison's 22e, p.687

SYNDROME CHROMOSOME(S) GENE PROTEIN KIDNEY TUMOR TYPE ADDITIONAL CLINICAL FINDINGS
von Hippel-Lindau
syndrome		 3p25 VHL von Hippel-Lindau protein Clear cell Hemangioblastoma of the retina
and central nervous system;
pheochromocytoma; pancreatic and
renal cysts; neuroendocrine tumors
7p31 MET MET Papillary
Hereditary
leiomyomatosis and RCC
(HLRCC syndrome)		 1q42 FH Fumarate hydratase FH-deficient/HLRCC syndrome–
associated RCC		 Leiomyoma; uterine leiomyoma/
leiomyosarcoma
17p11 FLCN Folliculin Chromophobe; clear cell;
oncocytoma
Tuberous sclerosis 9q34
16p13		 TSC1
TSC2		 Hamartin
Tuberin		 Angiomyolipomas; TSC-associated
lymphangioleiomyomatosis; rare
RCC with variety of histologic
appearances including eosinophilic
solid and cystic (ESC) RCC		 Angiofibroma, subungual fibroma;
cardiac rhabdomyoma; adenomatous
small intestine polyps; pulmonary
and renal cysts; cortical tuber;
subependymal giant cell astrocytomas
3p21 BAP1 BAP1 Mostly clear cell, but chromophobe
and papillary have also been
reported

TABLE 90-2 Classification of Malignant Epithelial Neoplasms Arising from the Kidney

Harrison's 22e, p.688

CARCINOMA TYPE CHARACTERISTIC GROWTH PATTERN CHROMOSOMAL EVENTS GENES WITH RECURRENT SOMATIC
ALTERATIONS
Clear cell Varying growth patterns, including acinar, solid
and sarcomatoid		 3p–, 5q+, 14q–, 9p– VHL, PBRM1, BAP1, SETD2
Papillary or sarcomatoid +7, +17, 9p–
Chromophobe Solid, tubular, or sarcomatoid Whole arm losses (1, 2, 6, 10, 13, 17,
and 21)		 TP53, PTEN, TERT promotor
Mimicking clear cell and papillary variants Xp11.2 translocations; t(6;11)
translocations
SMARCB1-deficient renal
medullary carcinoma		 Varying growth patterns, including cribriform,
reticular, sarcomatoid, adenoid, and microcystic		 +8q, 22q–, 22q translocations SMARCB1 (focal deletions, mutations,
gene fusions), SETD2