Papillary renal cell carcinoma | |
---|---|
Papillary renal cell carcinoma, type 1, characterised by tubulopapillary architecture with admixed foamy histiocytes in the papillary cores. | |
Specialty | Oncology |
Symptoms | Hematuria, flank pain, palpable abdominal mass |
Diagnostic method | Medical Image Test (ultrasound, computed tomography, magnetic resonance imaging) |
Treatment | Nephrectomy, partial nephretocmy, targeted molecular therapy |
Prognosis | 82-90% for five-year survival rate |
Papillary renal cell carcinoma (PRCC) is a malignant, heterogeneous tumor originating from renal tubular epithelial cells of the kidney, which comprises approximately 10-15% of all kidney neoplasms. [1] Based on its morphological features, PRCC can be classified into two main subtypes, which are type 1 (basophilic) and type 2 (eosinophilic). [2]
As with other types of renal cell cancer, most cases of PRCC are discovered incidentally without showing specific signs or symptoms of cancer. [3] In advanced stages, hematuria, flank pain, and abdominal mass are the three classic manifestation. [4] While a complete list of the causes of PRCC remains unclear, several risk factors were identified to affect PRCC development, such as genetic mutations, kidney-related disease, environmental and lifestyle risk factors. [5] For pathogenesis, type 1 PRCC is mainly caused by MET gene mutation while type 2 PRCC is associated with several different genetic pathways. [6] For diagnosis, PRCC is detectable through computed tomography (CT) scans or magnetic resonance imaging (MRI), which commonly present a small homogeneous hyposvascular tumor. [7] Nephrectomy or partial nephrectomy is usually recommended for PRCC treatment, often accompanied with several targeted molecular therapies to inhibit metastatic spread. [8] [9] PRCC patients are predominantly male with a mean age of 52–66 years. [10] When compared to conventional clear cell renal cell carcinoma (RCC), the prognosis of non-metastatic PRCC is more favorable, whereas a relatively worse outcome was reported in patients with metastatic disease. [11] Globally, the incidence of PRCC ranges between 3,500 to 5,000 cases, while it greatly varies depending on gender, age, and race/ethnicity. [12]
In 2014, PRCC was first acknowledged as a renal tumor subtype by the World Health Organization (WHO) considering its distinct genetic, molecular and histologic characteristics. [10] It is further divided into type 1 and type 2 based on morphological features. [13]
Type 1 PRCC, also known as a renal tumor caused by a genetic predisposition of hereditary papillary renal cancer syndrome, compromises approximately 25% of all PRCCs. [14] [15] In the perspective of immunochemistry, it has a profile of strong CK7 and alpha-methyl acyl-CoA racemase (AMACR) expression at most focal CA-IX expression. [16] Histologically, its epithelium is composed of relatively small-sized simple cuboidal cells lined in a single layer. [17] These cells are well-characterized by basophilic cytoplasm. [18] Due to its solid growth, an extremely compact papillary architecture is often observed. [16] Other morphological characteristics include intracellular hemosiderin and foamy macrophages placed inside of papillary fibrovascular cores or psammoma bodies. [19] In general, the nuclei of type 1 PRCC belong to grade 1-2 of the Fuhrman system. [16]
Accounting for 25% of PRCCs, type 2 PRCC is the pathological subtype that is most commonly associated with hereditary leiomyomatosis and renal cell carcinoma (HLRCC) syndrome. [14] [15] When compared to type 1, it shows more variation in protein expression mostly by loss of CK7. [16] In a gross examination, it shows papillae covered by large cells abundant in eosinophilic cytoplasm. [18] Its large spherical nuclei on papillary cores are arranged in a pseudo-stratified manner. [16] Unlike type 1 PRCC, foamy macrophages and psammoma bodies are less common in case of type 2. [15] The majority of type 2 PRCC has high Fuhrman grade nuclei with prominent nucleoli. [16]
Due to its asymptomatic nature, PRCC is often undetectable, and the majority of cases are incidentally diagnosed during the radiological workup of unrelated diseases. [3] [8] Its clinical manifestations are similar to those of clear cell RCC, which are the classical triad of renal cell carcinoma (hematuria, flank pain and palpable abdominal mass; only 6-10% of patients) or even nonspecific symptoms including fatigue, weight loss, fever, and anorexia. [4] [10] [21] Since early diagnosis is relatively uncommon, PRCC patients may experience symptoms caused by the metastatic spread to secondary sites. Specifically, metastasis occurs most frequently in the lungs followed by bone and the brain, exhibiting a wide range of symptoms including bone pain to a persistent cough. [8] [21]
Currently, the exact cause of PRCC remains unclear. Possible risk factors have been identified that contribute to PRCC development, which include genetic mutations, hereditary syndrome, renal injuries, and lifestyle factors. Germline mutation of c-MET oncogene and fumarate hydratase gene elevates the risk of type 1 and type 2 PRCC respectively through distinct signaling pathways. [22] [23] Regarding hereditary conditions, patients with hereditary papillary renal cancer syndrome showed a greater risk of type 1 PRCC, whereas those with hereditary leiomyomatosis and renal cell cancer (HLRCC) syndrome have an increased risk of type 2 PRCC. [24] [5] Moreover, patients who experienced chronic kidney diseases or acute kidney injury exhibited a higher incidence of PRCC. [25] [26] Additionally, other risk factors such as smoking, obesity, and high blood pressure can influence the pathogenesis of PRCC. [5]
Different molecular mechanisms are involved in PRCC development, which further result in distinct histologic features and clinical outcomes.[ citation needed ]
Type 1 PRCC is caused by a genetic mutation or a gain in chromosome 7 where the MET gene is positioned, resulting in the promotion of oncogenic pathways in renal epithelial cells. [6] Typically, the MET gene is upregulated for renal tissue repair and regeneration by encoding the receptor tyrosine kinase c-MET of hepatocyte growth factor. [6] However, activation of the oncogenic pathway in the MET gene will manifest invasion, anti-apoptosis, angiogenesis, and metastasis. [6]
Type 2 PRCC is associated with irregularity of several signaling pathways, which includes CDKN2A silencing, mutation in chromatin-modifying genes, and a GpG island methylator phenotype (CIMP). [27] CDKN2A is a tumor suppressor gene, while loss of its expression results in enhanced tumorigenesis and metastasis. [27] [28] Moreover, mutation of gene involved in chromatin remodeling (SETD2, BAP1, or PBRM) may lead to higher rate of TFE3/TFEB fusion. [27] Additionally, CIMP papillary renal cell carcinoma tumors exhibited somatic FH gene mutation, which is closely associated with HLRCC syndrome. [23]
Currently, cross-sectional imaging with computed tomography (CT) and magnetic resonance imaging (MRI) is known as the best option for diagnosing papillary renal tumors. [29]
Contrast-enhanced computed tomography (CT) is most commonly used to identify the subtypes of RCC. PRCC can be differentiated from other types of RCC due to its distinguishing features, displaying a small hypovascular renal tumor on T2 weighted images. [7] Typically, PRCC tends to appear homogeneous while clear cell RCC is likely to be in a heterogeneous form when the tumor is less than 3 cm in diameter. [30] Comparatively, in cases of tumors larger than 3 cm in diameter, PRCC is generally heterogeneous with areas of necrosis and hemorrhage compared to chromophobe RCC. [8] [31] Solid, small PRCC tumors (<3 cm in diameter) are more easily viewed on nephrographic, excretory phase images rather than on unenhanced, corticomedullary phase images. [8]
Magnetic resonance imaging (MRI) is recommended instead of CT for patients with an allergy to iodinated contrast materials. [8] As some renal tumors do not enhance significantly on CT, MRI examination is required to be performed with more sensitive contrast enhancement. [7] On MRI, the distinct features of PRCC are fibrous capsules and homogeneously low single intensity on both T1- and T2-weighted images. [8] [32] Specifically, PRCC exhibits hypointensity due to its dense collagenous matrix or deposition of calcium and hemosiderin within the tumor. [33] Such visual features help PRCC to be differentiated from clear cell RCC, which has heterogeneously higher single intensity shown on T2-weighted images. [8] [32] PRCC displays the smallest tumor-to-cortex enhancement at corticomedullary and nephrographic phases when juxtaposed with clear cell and chromophobe RCCs. [32]
The WHO/ISUP system is histological tumor grading system for renal cell carcinoma, suggested by the International Society of Urologic Pathologists (ISUP) in 2012 to diagnose tumor grades based on nucleolar prominence. [34] Currently recommended by the WHO, this four-tiered WHO/ISUP grading system has also been validated for PRCC. [34]
Grade | Definition |
---|---|
1 | Nucleoli are absent or inconspicuous and basophilic at 400 magnification. |
2 | Nucloeli are conspicuous and eosinophilic at 400 magnification and visible but not prominent at 100 magnification. |
3 | Nucleoli are conspicuous and eosinophilic at 100 magnification |
4 | There is extreme nuclear pleomorphism, multinucleate giants cells, and/or rhabdoid an/or sarcomatoid differentiation |
Earlier, the Fuhrman system was largely used, and was similarly based on nuclear features. [36]
First-line treatment for metastatic PRCC has not been standardized. Thus, similar treatment approaches for clear cell RCC have been used for PRCC, even though it has a distinct tumor histology. [9] [37]
Nephrectomy or nephron-sharing partial nephrectomy is widely recommended to reduce the risk of metastasis by eliminating all or part of the kidney. [8] Surgery procedures for PRCC depend on the patient's status and are very similar to procedures performed on RCC patients.[ citation needed ]
Several medications that target molecular pathways in RCC have been possible options for advanced and metastatic PRCC. [9] Among different medications, tyrosine kinase inhibitors (TKIs) and mammalian target of rapamycin (mTOR) inhibitors are effective in inhibiting angiogenesis, blocking growth and suppressing spread of the tumor. [38] Sunitinib, sorafenib, and axitinib are TKIs with anti-vascular endothelial growth factor (VEGF), which inhibit cellular signaling by targeting multiple receptor tyrosine kinase. [38] [39] [40] [41] Everolimus and temsirolimus are used in deregulating the mTOR pathway. [42] [43] Specifically, mTOR inhibitors have crucial roles in regulating cell growth, cell proliferation and metabolism of highly active tumor cells. [38] Other targeted agents such as MET inhibitors, epidermal growth factor receptor (EGFR) inhibitors, and monoclonal antibodies, are also promising treatment approaches for PRCC. [9] Foretinib is one example of a multikinase inhibitor targeting c-MET. [44] Considering that MET gene mutation is one oncogenic pathway of PRCC, MET inhibitors like tivantinib and volitinib are currently being investigated as a new targeted therapy option. [9] [44]
The five-year survival rate of PRCC has been reported as 82-90%, which is slightly higher than that of other kidney cancers. [45] The reduced survival rate has been positively correlated to several factors, which are high nuclear grade and stage, vascular invasion, DNA aneuploidy, and more. [46] Patients with type 1 PRCC have significantly improved survival rates than those with type 2, which is a reflection of its lower TNM stage with a well-encapsulated tumor. [47] Compared to other common types of RCC, PRCC exhibits a relatively lower risk of tumor recurrence and cancer-related death after nephrectomy. [48] Specifically, the cancer-specific survival rate at five years following surgery with PRCC has reached up to 91%, while clear cell RCC and chromophobe RCC were 72% and 88%, respectively. [46]
Among different histologic subtypes of RCC, PRCC is the second most predominant type and accounts for 10-15% of all renal tumors. [49] In the case of the United States, it is estimated that the incidence of PRCC will rise to 3,500 to 5,000 cases annually. [12] Generally, PRCC is more prevalent among men than women, while the reported sex ratio (M: F) varies from 1.8:1 to 3.8:1. [50] The mean age at presentation is identified as 52–66 years old; however, no statistically significant difference was found in the incidence of PRCC between the younger (< 40 years) and older adult groups (>40 years). [10] [51] In terms of racial variation, several studies have proven that people with African or Afro-Caribbean ancestry tend to have higher chances of being diagnosed with PRCC. According to the National Cancer Database, PRCC was more common in the Non-Hispanic Black population (38.9%) when compared to other races – Asian American (18.0%), Non-Hispanic White (13.2%), and Hispanic White populations (6.1%). [52]
Thyroid neoplasm is a neoplasm or tumor of the thyroid. It can be a benign tumor such as thyroid adenoma, or it can be a malignant neoplasm, such as papillary, follicular, medullary or anaplastic thyroid cancer. Most patients are 25 to 65 years of age when first diagnosed; women are more affected than men. The estimated number of new cases of thyroid cancer in the United States in 2010 is 44,670 compared to only 1,690 deaths. Of all thyroid nodules discovered, only about 5 percent are cancerous, and under 3 percent of those result in fatalities.
Endometrial cancer is a cancer that arises from the endometrium. It is the result of the abnormal growth of cells that have the ability to invade or spread to other parts of the body. The first sign is most often vaginal bleeding not associated with a menstrual period. Other symptoms include pain with urination, pain during sexual intercourse, or pelvic pain. Endometrial cancer occurs most commonly after menopause.
Renal cell carcinoma (RCC) is a kidney cancer that originates in the lining of the proximal convoluted tubule, a part of the very small tubes in the kidney that transport primary urine. RCC is the most common type of kidney cancer in adults, responsible for approximately 90–95% of cases. RCC occurrence shows a male predominance over women with a ratio of 1.5:1. RCC most commonly occurs between 6th and 7th decade of life.
Kidney cancer, also known as renal cancer, is a group of cancers that starts in the kidney. Symptoms may include blood in the urine, lump in the abdomen, or back pain. Fever, weight loss, and tiredness may also occur. Complications can include spread to the lungs or brain.
The collecting duct system of the kidney consists of a series of tubules and ducts that physically connect nephrons to a minor calyx or directly to the renal pelvis. The collecting duct system is the last part of nephron and participates in electrolyte and fluid balance through reabsorption and excretion, processes regulated by the hormones aldosterone and vasopressin.
Birt–Hogg–Dubé syndrome (BHD), also Hornstein–Birt–Hogg–Dubé syndrome, Hornstein–Knickenberg syndrome, and fibrofolliculomas with trichodiscomas and acrochordons is a human, adult onset, autosomal dominant genetic disorder caused by the FLCN gene. It can cause susceptibility to kidney cancer, renal and pulmonary cysts, and noncancerous tumors of the hair follicles, called fibrofolliculomas. The symptoms seen in each family are unique, and can include any combination of the three symptoms. Fibrofolliculomas are the most common manifestation, found on the face and upper trunk in over 80% of people with BHD over the age of 40. Pulmonary cysts are equally common (84%), but only 24% of people with BHD eventually experience a collapsed lung. Kidney tumors, both cancerous and benign, occur in 14–34% of people with BHD; the associated kidney cancers are often rare hybrid tumors.
Invasive carcinoma of no special type (NST) is also referred to as invasive ductal carcinoma or infiltrating ductal carcinoma(IDC) and invasive ductal carcinoma, not otherwise specified (NOS). Each of these terms represents to the same disease entity, but for international audiences this article will use invasive carcinoma NST because it is the preferred term of the World Health Organization (WHO).
Sunitinib, sold under the brand name Sutent, is an anti-cancer medication. It is a small-molecule, multi-targeted receptor tyrosine kinase (RTK) inhibitor that was approved by the FDA for the treatment of renal cell carcinoma (RCC) and imatinib-resistant gastrointestinal stromal tumor (GIST) in January 2006. Sunitinib was the first cancer drug simultaneously approved for two different indications.
Papillary thyroid cancer is the most common type of thyroid cancer, representing 75 percent to 85 percent of all thyroid cancer cases. It occurs more frequently in women and presents in the 20–55 year age group. It is also the predominant cancer type in children with thyroid cancer, and in patients with thyroid cancer who have had previous radiation to the head and neck. It is often well-differentiated, slow-growing, and localized, although it can metastasize.
Transitional cell carcinoma, also called urothelial carcinoma, is a type of cancer that typically occurs in the urinary system. It is the most common type of bladder cancer and cancer of the ureter, urethra, and urachus. Symptoms of urothelial carcinoma in the bladder include hematuria. Diagnosis includes urine analysis and imaging of the urinary tract (cystoscopy). Transitional cell carcinomas arise from the transitional epithelium, a tissue lining the inner surface of these hollow organs. When the term "urothelial" is used, it specifically refers to a carcinoma of the urothelium, meaning a transitional cell carcinomas of the urinary system.
Congenital mesoblastic nephroma, while rare, is the most common kidney neoplasm diagnosed in the first three months of life and accounts for 3-5% of all childhood renal neoplasms. This neoplasm is generally non-aggressive and amenable to surgical removal. However, a readily identifiable subset of these kidney tumors has a more malignant potential and is capable of causing life-threatening metastases. Congenital mesoblastic nephroma was first named as such in 1967 but was recognized decades before this as fetal renal hamartoma or leiomyomatous renal hamartoma.
Collecting duct carcinoma (CDC) is a type of kidney cancer that originates in the papillary duct of the kidney. It is rare, accounting for 1-3% of all kidney cancers. It is also recently described; a 2002 review found just 40 case reports worldwide. Previously, due to its location, CDC was commonly diagnosed as renal cell carcinoma or a subtype of renal cell carcinoma. However, CDC does not respond well to chemotherapy drugs used for renal cell carcinoma, and progresses and spreads more quickly.
Renal medullary carcinoma is a rare type of cancer that affects the kidney. It tends to be aggressive, difficult to treat, and is often metastatic at the time of diagnosis. Most individuals with this type of cancer have sickle cell trait or rarely sickle cell disease, suggesting that the sickle cell trait may be a risk factor for this type of cancer.
Kidney tumours are tumours, or growths, on or in the kidney. These growths can be benign or malignant.
Targeted therapy of lung cancer refers to using agents specifically designed to selectively target molecular pathways responsible for, or that substantially drive, the malignant phenotype of lung cancer cells, and as a consequence of this (relative) selectivity, cause fewer toxic effects on normal cells.
Adenocarcinoma of the lung is the most common type of lung cancer, and like other forms of lung cancer, it is characterized by distinct cellular and molecular features. It is classified as one of several non-small cell lung cancers (NSCLC), to distinguish it from small cell lung cancer which has a different behavior and prognosis. Lung adenocarcinoma is further classified into several subtypes and variants. The signs and symptoms of this specific type of lung cancer are similar to other forms of lung cancer, and patients most commonly complain of persistent cough and shortness of breath.
Mucinous tubular and spindle cell carcinoma (MTSCC) is a rare subtype of renal cell carcinoma (RCC), that is included in the 2004 WHO classification of RCC. MTSCC is a rare neoplasm and is considered as a low-grade entity. It may be a variant of papillary RCC. This tumor occurs throughout life and is more frequent in females.
Hereditary leiomyomatosis and renal cell carcinoma (HLRCC) or Reed's syndrome is rare autosomal dominant disorder associated with benign smooth muscle tumors and an increased risk of renal cell carcinoma. It is characterised by multiple cutaneous leiomyomas and, in women, uterine leiomyomas. It predisposes for renal cell cancer, an association denominated hereditary leiomyomatosis and renal cell cancer, and it is also associated with increased risk of uterine leiomyosarcoma. The syndrome is caused by a mutation in the fumarate hydratase gene, which leads to an accumulation of fumarate. The inheritance pattern is autosomal dominant and screening can typically begin in childhood.
Squamous-cell carcinoma (SCC) of the lung is a histologic type of non-small-cell lung carcinoma (NSCLC). It is the second most prevalent type of lung cancer after lung adenocarcinoma and it originates in the bronchi. Its tumor cells are characterized by a squamous appearance, similar to the one observed in epidermal cells. Squamous-cell carcinoma of the lung is strongly associated with tobacco smoking, more than any other forms of NSCLC.
Toni K. Choueiri is a Lebanese American medical oncologist and researcher. He is the Jerome and Nancy Kohlberg Professor of Medicine at Harvard Medical School and Director of the Lank Center for Genitourinary Oncology at the Dana–Farber Cancer Institute. His work has led to the establishment of several novel drugs and prognostic factors in advanced renal cell carcinoma (RCC). Choueiri also co-established the International metastatic database Consortium with Daniel Heng. His biomarker work has shed light on complex immunogenomics mechanisms contributing to response and resistance to targeted therapy and immunotherapy.