Polynesian countries collectively have a high death rate from breast cancer because of late detection of the disease, Mr Paul Kitchen MA MB BS FRACS, a breast cancer surgeon from Australia said in Nuku'alofa this week.

Some 43% of all breast cancer sufferers in Polynesia will die from the disease compared to 22% in Australia and an overall 36% death rate for the world.

Mr Kitchen spoke on "Shedding Light on Cancer" on May 11 in a public lecture organised by the Tonga Breast Cancer Society and a surgeon resident in Tonga, Dr Veronique Laloe.

"Breast cancer is the most common cause of cancer-related death among women worldwide, with case fatality rates highest in low-resource countries," he said.

Mr Kitchen is semi-retired but still attends the breast clinic at St Vincent's Hospital, Melbourne, Australia where he is a senior lecturer in surgery in the Breast & Endocrine Unit. He was a surgeon at the BreastScreen program in Melbourne and on committees at the Cancer Council of Victoria.

He said the incidence of breast cancer has doubled over 25 years and that one in nine Australian women will develop breast cancer and that one in 38 women will die from it before the age of 85 years.

Breast cancer was increasing because of improved detection and other factors such as decreased childbearing and breast-feeding; Increased exogenous hormone exposure; and detrimental dietary and lifestyle changes including:

• obesity and less physical activity
• alcohol consumption
• smoking
• and, perhaps, shift work with prolonged night exposure to artificial light

Myths about cancer

He spoke about common myths surrounding cancer, and pointed out that only a small percentage of people who were diagnosed with the disease had a family history of it.

Anyone could get cancer and diet and smoking were big contributors to the disease. In Australia some 95% of cases were detected after the age of 40 years and 60% of cases were detected after the age of 60 years.

"The chance of Australians developing cancer before 75 is for males a 1 in 3 chance and for females a 1 in 4 chance."

He said that in the USA where 120 people a day die of cancer, it was the second top cause of death in 2008 and caused more deaths in the 1990s than all the major wars at the time combined.

Defective genes

He said that cancer was caused by defective genes.

"Cancer is a genetic disease but that doesn't mean that it runs in the family but it means there is something wrong with the genes. . . . It doesn't necessarily get passed on."

He said that genes could be affected by all sorts of things such as ultraviolet exposure from the sun, nuclear radiation, asbestos, chemicals, tobacco tar, industrial agents and viruses.

"It is a genetic disease which causes abnormal accumulation of cells which have the ability to invade tissues. Cancer cells fail to die and keep multiplying," he said.

In Victoria, breast cancer trends were increasing but he said it was now possible in Australia to find tumours when they were very small and to diagnose them so that it can be removed without losing the breast.

"Patients are presenting earlier so they are not dying," he said.

Tongan screening

Tongan women present at the meeting discussed screening methods, including self-examination. Tonga does not have sophisticated equipment or staff to do mammograms.

Mr Kitchen was visiting Tonga from May10-16 on holiday with his wife, Rev. Merrill Kitchen, a theologian.