What is Hereditary Papillary Renal Cancer?
Hereditary papillary renal cancer is one category of renal carcinoma that is slowly emerging worldwide on a yearly basis. Hereditary papillary renal cancer is an autosomal dominant syndrome. The affected individuals have a predisposition towards developing multifocal, bilateral type 1 papillary renal cancer.(1, 2)
Symptoms of Hereditary Papillary Renal Cancer
In the condition of hereditary papillary renal cancer, often both the kidneys get affected. This is a condition where each of the kidneys could have more than one tumor. Symptoms of hereditary papillary renal cancer can vary from person to person in their nature and also to its extent. Hereditary papillary renal cancer often might not elicit symptoms in the earlier stages. Moreover, there are no typical or routine tests that can be conducted to trace the existence of renal cancer at its earlier stage. However, at a later stage, the symptoms of hereditary papillary renal cancer could be one or more of the following:(3)
- Color of the urine could turn into pink or that of red, indicating at the presence of blood in the urine
- Pain in the lower back which continues to persist.
- Loss of appetite
- Sudden and unexplained loss of weight
- Tiredness or fatigue throughout the day, often unexplained
- Intermittent fever.
Causes of Hereditary Papillary Renal Cancer
As the name of the condition explains, this is a hereditary condition that occurs due to the mutation of genes. This autosomal dominant condition is quite difficult to predict and could get transmitted to various members and generations of a family due to various reasons. Reasons behind the mutation of genes are a rather complex area and further researches are being conducted to get a better understanding of the condition.
Hereditary papillary renal cancer is often found to be causally associated with germline mutations of the MET gene on 7q31.(4-6) Due to mutation, the cells divide and grow at a very high speed. The accumulation of the abnormal cells often leads to the formation of a tumor that either stays within the kidney or sometimes extends beyond the kidneys to other parts of the body.(3, 7)
Risk Factors of Hereditary Papillary Renal Cancer
There are certain risk factors that happen to contribute to the occurrence of the condition like:(3)
- Increased body weight and obesity
- Increasing age
- High blood pressure or hypertension
- Prolonged kidney treatment of some type
- Presence of genetic conditions like von Hippel-Lindau syndrome
- A family history of the same disease, etc.
Diagnosis of Hereditary Papillary Renal Cancer
There are designated and definite tests and checkups that are conducted to diagnose hereditary papillary renal cancer. It does not require mentioning that mere clinical checkups cannot clearly indicate the condition. Hence the following tests are conducted.
Urine and Blood Test to Diagnose Hereditary Papillary Renal Cancer: The very first type of tests that are prescribed by a doctor is the urine and blood test that will give the doctor a clear picture to rule out other conditions and help in identifying the other problems that one is having.
Imaging Tests: These days a number of different imaging tests are given so that the doctor can get a proper image of your kidneys and the growths that have developed within them. Some of the tests of imaging given by doctors in such conditions are those of computerized tomography or CT, ultrasound and that of magnetic resonance imaging or MRI.(7)
Biopsy to Diagnose Hereditary Papillary Renal Cancer: In this form of testing, a small portion of the cells of the suspected area of the kidneys are collected. This sample is then tested in the laboratory to find traces of cancer in them. This process is known as a biopsy.
Epidemiology of Hereditary Papillary Renal Cancer
In the earlier times, hereditary renal cancers was said to contribute to a mere 3 to 5% of the number of kidney cancer cases. However, these days the number of cases of hereditary papillary renal cancer has been found to be increasing.(6) The rate of renal cancer in patients has doubled from 1995, going from 3 per 1,00,000 to 6 per 1,00,000.(8) It can also be said that the probabilities or the characteristic features of the families that seem to get affected by the condition are also increasing and getting all the more diversified. This is making the task of finding the roots or the origin of the mutated genes all the more difficult for the scientists and the doctors. Hereditary papillary renal cancer accounts for almost 10-15% of all renal cancers.(9)
Treatment of Hereditary Papillary Renal Cancer
Treatment for hereditary papillary renal cancer can be a prolonged one and can include a wide variety of different treatment procedures. At the very onset of the process of treatment often the doctor and his entire team sit with the patient and discuss the course of treatment beforehand. This prepares the patient and his or her family mentally for the procedure in terms of the time and the money that will be required for the procedure.(3, 6, 7) The nature of the treatment of hereditary papillary renal cancer often depends on the stage and the nature of the ailment, the overall physical condition of the patient and other such factors. The treatment methods for hereditary papillary renal cancer include:
Surgery: The main treatment procedure for hereditary papillary renal cancer or the initial step is always the surgery that either removes the entire kidney that has been affected or a certain portion of the kidney. It could either be an open nephrectomy where a big incision is done on the abdomen or the process could be done through robotic laparoscopy. The decision will depend on the nature of the ailment and the exact requirement for the patient.
Nonsurgical Treatments to Manage Hereditary Papillary Renal Cancer: In certain cases, surgery is not considered to be an option for hereditary papillary renal cancer where the tumors are destroyed without using any surgical processes. In one of the procedures, the cancer cells are frozen. This process is known as cryoablation. In this process, a special thin needle is inserted through the skin right into the kidneys and cold gas is used to freeze the cancer cells. In certain situations, radiofrequency ablation is performed which is heating of the cancer cells using ultrasound. An electric current is passed through the needle causing it to get heated up and then get burnt. These processes are good for patient who either can’t have surgery or has really small tumors.
Other Therapies for Hereditary Papillary Renal Cancer: There are a host of other therapies that are often required and even continued side by side. These therapies are those of radiation, immunotherapy, and target therapy and so on.
On a concluding note, it can be said that hereditary papillary renal cancer is one of the most complex and fascinating domains which becomes all the more critical to deal with due to the involvement of the genes and the DNA. If diagnosed early, the prognosis of hereditary papillary renal cancer is really good (10); however, in cases of metastasized cancer, the prognosis lowers. This is a highly complex domain and will require larger investigations and research for more solid and concrete, consolidated answers and findings.
- Nathanson KL. (2015) Hereditary renal cancer syndromes. Onco-Nephrology Curriculum, American Society of Nephrology. 130: 97-103.
- Zbar B, Tory K, Merino M, et al. (1994, Mar) Hereditary papillary renal cell carcinoma. The Journal of Urology. 151(3): 561–566.
- Schmidt L, Duh FM, Chen F, et al. (1997, May) Germline and somatic mutations in the tyrosine kinase domain of the MET proto-oncogene in papillary renal carcinomas. Nature Genetics. 16 (1): 68-73.
- Schmidt L, Junker K, Nakaigawa N, et al. (1999, Apr) Novel mutations of the MET proto-oncogene in papillary renal carcinomas. Oncogene. 18(14):2343–2350.
- Howlader N, Noone AM, Krapcho M, Garshell J, Miller D, Altekruse SF, Kosary CL, Yu M, Ruhl J, Tatalovich Z, Mariotto A, Lewis DR, Chen HS, Feuer EJ, Cronin KA. SEER Cancer Statistics Review, 1975-2012, Bethesda, MD, National Cancer Institute, 2015.
- Michael B Atkins, Toni K Choueiri. (2015, Nov) Epidemiology, pathology, and pathogenesis of renal cell carcinoma. UpToDate.