Patients seek help earlier, so tumours are smaller and kidneys can be saved
MORE people here are coming down with renal cell cancer, a fairly rare cancer that presents few obvious symptoms until it is quite advanced. In the five years between 1993 and 1997, 294 cases of this type of kidney cancer surfaced, but in the next five years, the figure shot up to 449; between 2003 and 2007, it rose yet again to 593. The number of cases for every 100,000 people has thus also gone up – from 3.82 in the first five-year period to 6.88 between 2003 and 2007, noted Professr Chia Kee Seng, who heads the epidemiology and public health department at the National University of Singapore (NUS) Yong Loo Lin School of Medicine. That was an 80 per cent rise.
The silver lining in this is that patients are seeking medical help much earlier, when the cancer is still confined to the kidney. Associate Professor Chia Sing Joo, divisional chairman of surgery at Tan Tock Seng Hospital (TTSH), puts this down to a heightened awareness among people of what being in good health feels like: People now go to their doctor when they see blood in their urine or suffer from bad lower backaches, instead of just ignoring or enduring these symptoms.
Among those for whom kidney cancer has been identified as the source of the trouble, two in three are diagnosed with renal cell cancer, where a tumour forms in the linings of the tiny tubes in the kidney, which are supposed to filter the blood and remove waste from it. Other kinds of kidney cancers are renal pelvis cancer, where a tumour forms in the centre of the kidney where urine collects, and Wilms’ tumour, which usually develops in children under the age of five.
NUS’ Prof Chia said obesity, a smoking habit and advancing age are risk factors for cancer in general, and kidney cancer is no exception. Foreign studies have found that people of African or South Asian descent are more susceptible to this type of cancer. Being male is also a risk factor; men are twice as likely to get it. The difficulty in diagnosing the disease stems from its lack of early symptoms. Those with a family history of it thus need to be more aware; individuals whose family the disease runs in can get it as early as in their teens.
Screening the abdomen is one way of catching the disease, but screening procedures may also pick up harmless cysts. As it usually takes up to 1 1/2 years for a centimetre-wide tumour to spread beyond the kidney, doctors may recommend a follow-up screening a few months later for a better picture of whether the growth is benign or cancerous. Even then, there is a 2 per cent chance that the lump will be found to be benign upon removal. Unlike breast cancer, renal cell cancer cannot be treated with chemotherapy or radiotherapy. Surgery is generally the treatment of choice. If the cancer has already spread beyond the kidney to other parts of the body, including the brain and the heart, a new type of chemotherapy is administered. This has been found to help four in 10 patients.
But six in 10 patients whose renal cancer has spread die in months or years. TTSH’s Prof Chia said that because more patients are seeking help early enough while their tumours are relatively small, improved surgery techniques have saved their kidneys. He said that in the late 1980s, when he was still a young surgeon, patients were turning up with tumours the size of a football – up to 30cm in diameter. He remembers a case in which a kidney tumour weighed 7.6kg.
Today, about 60 per cent of patients have tumours that are 5cm or smaller. At TTSH, the median size of tumours in 2003 was 8cm; of the six cases the hospital treated in the first two months of this year, the median size was less than half of that – at 3.4cm, said Prof Chia.