PROSTRATE CANCER

The first vaccine for prostate cancer — one of the major tumours affecting middle-aged and elderly Kenyan men — could be in the market within weeks.

The vaccine, Provenge, which could get approval by the US Federal Drug Agency before the end of this month, has been shown in human trials to prolong life.

Trials showed that although most men given the vaccine lived just four and a half months longer, some gained an extra two to three years of life.

Oral tumours

The disease affects about 1,000 men in Kenya annually and is the most deadly cancer for men after oral tumours. The cancer is estimated to kill 850 men in Kenya every year and the figure is climbing in tandem with other cancers.

Tumours of the lip, mouth, tongue and throat, also called oral cancers, are highest in men locally, according to figures from the Nairobi Cancer Registry.

A study carried out by the Kenya Medical Research Institute last year found that of the 2,292 cancer related deaths recorded in Nairobi during a two-year period, oral tumours claimed the most.

Studies on the new vaccine, developed by Dendreon Corp of the US, showed it improved survival by 38 per cent. Unlike traditional vaccines that prevent disease, Provenge treats it by stimulating the body’s own immune system to attack cancer cells.

It is produced by taking cells from a patient’s tumour, incorporating them into a vaccine, then returning them to a physician to be injected back into the patient. The FDA is slated to decide by May 1, whether to approve Provenge for treating advanced prostate cancer.

For two reasons the vaccine may be good for Kenya; first, Kenyans usually present themselves before a physician during advanced stages, and, second prostate cancer has been shown to be highest among Africans compared to other races.

Africans and men of African extraction are thought to be more prone to the disease because of their genetic make-up. The gene responsible is called ODC with a certain variant found in higher frequency in indigenous Africans and men of African ancestry compared to other races.

Writing in a special supplement of the East African Medical Journal, Prof George Magoha, a urologist who is also the vice-chancellor of the University of Nairobi, said studies had established that indeed Africans are more prone to the disease.

“Prostate cancer incidence and mortality is higher for Africans in the diaspora than all other races in the world,” wrote Prof Magoha in a past issue of the journal.

The urologist had compared his experience at Kenyatta National Hospital with the Nigerian studies and found similarities in the rates. He also noted that Kenyans with the cancer presented themselves to hospitals when it was too late for effective management.

This was true for about 85,000 patients examined at Kenyatta Hospital for one year. Eighty seven per cent sought treatment when the disease was at an advanced stage. Ages affected started from 50 years peaking at between 66 and 70.