Unit 1.3 – Renal Cancers

There are several different types of renal cancer. The most common is renal cell carcinoma (RCC) and this accounts for more than 80% of all renal cancers in the UK. There are eight sub-types of RCC, which are classified according to the appearance of the cancer cells under the microscope; these include clear cell, which is the most common RCC sub-type (75-80%), pa​​pillary (chromophilic 10-15%), chromophobe (5%), collecting duct, renal medullary carcinoma, mucinous tubular and spindle-cell carcinoma, renal translocation carcinoma, and unclassified RCC (the latter five of which are very rare and make up the remaining 5-10% of RCC tumours). Nephroblastoma (or Wilms’ tumour) is a renal cancer found in children, usually between the ages of 2 and 5.

Incidence rates for kidney cancer in the UK are highest in people aged 85 to 89 between 2016-2018. In males in the UK, kidney cancer is the 5th most common cancer, with around 8,400 new cases between 2016-2018.In females in the UK, kidney cancer is the 10th most common cancer, with around 4,900 new cases between 2016-2018. ^[1]

Kidney cancer risk is 24% higher in men per 5-unit body mass index increase, and 33% higher in women per 5-unit body mass index increase. ^[2] 13% of kidney cancer cases in the UK are caused by smoking. ^[3]

Certain medical conditions and treatments can increase the likelihood of developing renal cancer; these include cystic kidney disease, dialysis, renal stones, hypertension, and previous abdominal radiotherapy (for example, for testicular or cervical cancer). A diet low in fruit and vegetables can also have a higher risk. There are also some inherited diseases that can give a higher risk of developing renal cancer. These include von Hippel-Lindau (VHL) syndrome, Birt-Hogg-Dubé syndrome, and hereditary papillary RCC (HPRCC).

Unlike some cancers, such as breast cancer, which has a very effective screening programme in some countries, there is no screening programme for RCC. A renal ultrasound scan could be used as a screening tool for RCC; however, the incidence of RCC in the UK does not warrant a dedicated screening programme. The advantage of early detection is successful removal of the affected kidney to prevent the spread of the disease. In England more than 85% of people at stage 1 survive their cancer for 5 years or more after they are diagnosed, 75% at stage 3, and only 10% at stage 4 between 2013-2017 [4]

According to Cancer research UK, there are around 13,332 new kidney cancer cases in the UK every year, and there are around 4,631 kidney cancer deaths in the UK every year (2016-2018). Kidney cancer is the 7th most common cancer in the UK, accounting for 4% of all new cancer cases (2016-2018). In females in the UK, kidney cancer is the 10th most common cancer (3% of all new female cancer cases). In males in the UK, it is the 5th most common cancer (4% of all new male cancer cases). It is therefore considered a rare cancer. Over the last decade, kidney cancer incidence rates have increased by more than 29% in the UK. Rates in females have increased by more than 28%, and rates in males have increased by around 26% between 2016-2018.[1]

In part, this may be because people are living longer and we have better scanning facilities so are finding smaller, asymptomatic tumours. Also, the increased use of imaging modalities, in particular CT, has resulted in an increase in the incidental discovery of renal tumours during routine scans for unrelated conditions. In the USA, this accounts for 60-70% of renal tumours. However, research in both the USA and the UK has suggested that there is an underlying increase in the incidence of renal cancer, which cannot be explained simply by improved detection. Changes in lifestyle factors, such as smoking and obesity, may also impact the increasing incidence of renal cancer.

There are more than 400 000 new cases of kidney cancer diagnosed worldwide every year. There is an increasing trend for kidney cancer incidence globally, particularly in European countries and the younger population[5].

Worldwide, Lithuania had the highest overall rate of kidney cancer in 2020, followed by Czechia (formerly known as the Czech Republic), Uruguay, Estonia and Slovakia.[6]

Though renal cell carcinoma (RCC) accounts for 2% of global cancer diagnoses and deaths, it has more than doubled in incidence in the developed world over the past half-century, and today is the ninth most common neoplasm in the United States. While North America and Western Europe have the highest disease burden, Latin America, Asia and Africa are projected to see an increase in incidence as nation’s transition to a Western lifestyle [7].