Cancer rates to fall among men but slightly rise among women by 2020: Report

By Dr. Ananya Mandal, MDMar 11 2012

According to a new report the incidence of cancer in Australian men is expected to fall over the next decade while women will experience slightly higher rates of the disease by 2020.

The report says that due to the growing and ageing population the actual number of new cases will rise by almost 40 per cent on 2007 levels. But when that's converted to the number of cases per 100,000 people the results are surprising. Cancer rates in men will fall from 595 to 568 cases per 100,000 by 2020. That equates to about 85,000 cases. When it comes to women the rate is projected to rise from 394 to 408 cases per 100,000. That's equivalent to 65,000 new cases in 2020.

The overall incidence for men is expected to drop due to stabilization in the rate of prostate cancer, which accounts for 30 per cent of all new diagnoses in men. It's the most common cancer for males and the second deadliest behind lung cancer. Over the past two decades there have been a number of spikes in prostate cancer related to early detection and, later, improvements in diagnostic procedures and the number of biopsies being conducted. The rate is expected to continue to rise through until 2020 but only to 164 new cases per 100,000 men which is well below the 1994 and 2007 peaks of 184 and 183 cases respectively. But by the end of the decade that means there'll be 25,300 cases of prostate cancer each year.

In addition lung cancer rates will actually decline in men as well. For women, breast cancer will continue to be the most common cancer diagnosed in 2020 with 17,200 cases in total. It will likely be followed by bowel cancer (9200 cases), melanoma (6800) and lung cancer (6100). Rates for liver cancer are projected to increase by 38 per cent by 2020 in males and 78 per cent in females. Thyroid cancer is expected to increase by 33 per cent in males and 62 per cent in females.

The latest figures from the Australian Institute of Health and Welfare (AIHW), released on Friday, also set out which cancers are expected to have the largest rises and falls. AIHW cancer unit head Chris Sturrock says the uptick in liver cancers could be related to increasing rates of hepatitis B and hepatitis C. Experts aren't sure why thyroid issues are on the rise.

On the positive side, however, stomach cancers are expected to fall by 25 per cent for men and 20 per cent for women. That's likely due to early intervention catching problems before they turn cancerous. “There's been a lot of advances around treatment for stomach ulcers and there seems to be an association with stomach cancer there,” Ms Sturrock said.

The Australian population has been increasing since 1982 and is expected to exceed 25 million by 2020. Cancer primarily occurs in people aged 65 and over and that figure jumped from 10 to 13 per cent of the population in the 25 years to 2007. The over 65s are expected to comprise 17 per cent of the population by 2020. “The (overall) number of cancers is going up because the population is increasing and particularly the older population is increasing,” Ms Sturrock said. “Cancer is primarily a disease of older people so the more older people we have the more cases we'll have.”

Sydney medical oncologist David Goldstein, a former president of the Clinical Oncological Society of Australia, said the ratio of patients to cancer doctors was already too low and increases on the scale of those forecast would further strain the system.

Cancer Council Australia chief Ian Olver said the forecast increase would put a strain on these services, because the proportion of patients recommended to receive radiotherapy and chemotherapy would still be about 50 per cent in both cases. “If you have more people, you have to provide more services,” Professor Olver said. “It may mean workforce redesign - people are saying there should be colonoscopy technicians, so maybe you keep doctors for the higher-end decision-making and have other people that can be trained to do the other work.”

Professor Olver said the projections also represented a strong argument for government action to improve cancer detection and prevention. He said the national bowel cancer screening program, which was introduced in 2006, could save far more people than the 4000 who were found to have pre-cancerous or more advanced lesions were it to be rolled out in the more extensive form cancer experts had long recommended.

“I think they have issued a challenge to see if we can do something about it, by making the changes we know will work - and the first one I would attack would be bowel cancer screening,” he said. Professor Olver said the figures concealed the fact that death rates for most cancers continued to fall.