In what was a first for Sunshine Coast Hospice, they hosted a cancer awareness talk by American MD Steve Kennedy at the Royal Port Alfred Golf Club during the recent Hospice Week.
Kennedy said there were more than 200 kinds of cancer. In South Africa, according to Cansa statistics from 2014, the most common cancer in men was prostate cancer (19%), while in women it was breast cancer (22%).
The next highest incidences of cancer in men are colorectal (5%), lung (5%), Kaposi’s (3%) and cancer of the oesophagus (2%).
In women, the next highest prevalence is cervical cancer (15%), colorectal cancer (4%) and lung cancer (3%).
The death rates for cancer among men in South Africa, according to SA Medical Research Council figures from 2000, are 22% for lung cancer, 17% for cancer of the oesophagus, 12% for prostate cancer and 5% for colorectal cancer.
In women, the death rates in declining order are cervical (17%), breast (16%), lung (11%), oesophagus (10%) and colorectal (7%).
Kennedy said in the US, cancer death rates had been on a downward trend since the early 1990s. He said contributors to this decrease were early detection (screening), improved therapies, and people making healthier choices – as an example he said the percentage of US adults who smoked had decreased from 42% in 1963 to 14% in 2017.
As for the benefits of screening, he said screening for breast cancer decreased mortality by 30-45%, depending on the age of the person. With an earlier diagnosis the cancer is in a lower stage and requires less intervention with a better outcome.
Examples of screening are self-examination, clinical examination, and then imaging, which include the options of mammography, ultrasound (useful for dense breast tissue) and an MRI for high risk patients, but which gives more false positives.
The benefit of early detection for colorectal cancer is a five year survival rate of 90% if the cancer is localised, 71% if it’s regional. But this goes down to 14% if the cancer has spread.
Kennedy said in the US, the incidence of colorectal cancer had gone down 2.5% a year between 1990 and 2007, and mortality had gone down 35%.
Screening among US adults had risen from 42% in 2000 to 59% in 2010.
Examples of screening are a faecal occult blood test (18-32% mortality reduction), flexible sigmoidoscopy (41% mortality reduction), colonoscopy (68% mortality reduction).
Screening is recommended from age 45 – earlier if high risk.
An emerging trend in medicine was to approach prostate cancer differently than in the past.
“Not all men diagnosed with prostate cancer require therapy,” Kennedy said. “It’s a disease one dies ‘with’, not ‘of’.”
A US Medicare records study had shown that in older men diagnosed with prostate cancer who had no curative therapy, about 8-26% had died from prostate cancer, while 60% had died from competing causes.
Screening is carried out by a digital rectal exam or the more popular prostate specific antigen (PSA) blood test.
Kennedy said among the risks for prostate cancer screening were unnecessary biopsies, over-diagnosis of innocuous lesions, overtreatment and equivocal mortality benefit.
The US Preventative Services Task Force had recommended no routine PSA screening, while the American Cancer Society had taken a more nuanced approach of informed discussion and screening high risk patients with a greater than 10-year life expectancy.
As for types of cancer treatment, radiation therapy had progressed over the past 40 years with higher energies and more specific targeting of lesions, Kennedy said.
In chemotherapy, new agents are being used in new combinations, as well as biologically engineered drugs/ antibodies, and there is better supportive care.