Cutting edge cancer research

  • Eimear Vize


Ireland's cancer researchers are making significant advances internationally in the understanding and treatment of cancer.

Our top cancer investigators showcased their research at the prestigious annual meeting of the American Society of Clinical Oncology (ASCO) in Chicago recently.

Just over 50 Irish studies were accepted for presentation to the world's oncology community, including research that showed men with prostate cancer taking higher doses of aspirin lived longer.

Experts from Trinity College Dublin and the National Cancer Registry Ireland examined outcomes for more than 1,100 men who had been taking aspirin regularly before they were diagnosed with prostate cancer.

They found that those patients taking higher doses of aspirin (more than 75mg) had a significant reduction in cancer-related deaths compared to men on a small daily dose (75mg).

Research by doctors at Waterford Regional Hospital revealed that younger patients with colon cancer were four times more likely to receive adjuvant chemotherapy (AC) than their older counterparts, despite a survival benefit also being seen in older patients.

Adjuvant chemotherapy is treatment of the tumour with drugs after surgery to kill as many of the remaining cancer cells as possible.

Of the 2,000 patients identified nationally from 2004-2009, AC was used in 10% of patients 70 years and older, and in 40% of younger patients, confirming that the patient's age can impact on the doctor's treatment decisions regardless of survival benefit in older patients.

Doctors at the Mater Hospital in Dublin, who reviewed the medical records of 25 women diagnosed with cancer in pregnancy over a 25-year period, found that there were no adverse outcomes in mothers or infants exposed to chemotherapy during pregnancy.

The authors remarked: "We identified a cohort of patients that do not need immediate treatment during pregnancy. In selected cases, it is safe and appropriate to delay chemotherapy until delivery of the baby. There were no adverse outcomes to mothers due to delayed treatment and no adverse outcomes to babies not exposed to chemotherapy in utero."

A high-rate of inappropriate prescribing among older cancer patients attending cancer day-wards was identified a study involving researchers at five hospitals in Cork, Waterford, Kilkenny, and Tipperary.

Medication lists were collected from 96 patients (average age 75 years) over a three month period. A total of 34 inappropriate prescriptions were prescribed in 30% of patients, the most common of which was an anti-nausea and vomiting drug (29%).

Meanwhile, research from India, which demonstrated the remarkable live-saving benefits of a simple vinegar test in detecting ovarian cancer, was one of the highlights of the ASCO conference.

The vinegar test cut cervical cancer deaths by one-third, according to Dr Surendra Shastri, professor of preventive oncology at the Tata Memorial Hospital in India, who led the research.

He said this cheap form of screening, which can be done by trained non-medical personnel, could prevent at least 72,000 deaths from cervical cancer worldwide each year.

Wealthy countries have succeeded in reducing cervical cancer deaths by 80% thanks to the widespread use of regular Pap smears, however cervical cancer remains the leading cause of cancer death among women in India and many other developing countries because of the scarcity of money, doctors, nurses and laboratories.

Dr Shastri and colleagues set about testing VIA - visual inspection with acetic acid - as an affordable alternative to Pap smears in a large-scale cervical cancer screening programme, launched in 1998 and enrolling more than 151,000 women from the Mumbai slums.

He told the Chicago conference that sixty seconds after applying acetic acid to the cervix using a cotton swab, precancerous lesions turn white and can be discerned from pink healthy tissue with the naked eye - something that primary health workers can easily be trained to identify with high accuracy.

He reported that VIA enabled diagnosis at an earlier stage of the disease and hence earlier treatment, which translated into survival gains. Use of VIA significantly reduced the rate of cervical cancer mortality from 16.22 to 11.12 deaths per 100,000 women-years of observation - that's a 31% reduction compared with the control group.

Patients with advanced melanoma, the deadliest type of skin cancer, were give new hope in the form of the first cancer-killing virus designed to trigger the body's immune system to attack melanomas.

According to study results presented at ASCO, 16% of the patients who received the drug, called talimogene laherparepvec, or TVEC, experienced a significant shrinkage of their tumours that lasted at least six months. That compared with only 2% of the patients in a control group.

TVEC is a modified herpes simplex virus - the type that causes cold sores - designed as a Trojan horse to infiltrate and destroy tumours by wielding a 'one-two punch' - directly killing tumour cells at the site of injection, while also teaching the immune system to recognise melanoma cells and seek them out and destroy them elsewhere in the patient's body.

A large US study found that breast cancer patients can obtain the same disease control but with less harmful side effects when they receive weekly low-dose chemotherapy compared to a dose-dense regimen every two weeks.

The low-dose weekly schedule was far less toxic than the dose-heavy bi-weekly schedule in terms of neurologic events (17% versus 10%), musculoskeletal pain (11% versus 3%) and allergy (1.4% versus 0.6%)

However, when researchers looked at the five-year progression-free survival (PFS) rates, they were practically identical for patients given low-dose chemotherapy weekly (82%) and a higher dose every two weeks (81%).

Updated results from a separate breast cancer study - the aTTom trial - found that women with early-stage breast cancer, who took the drug tamoxifen for a longer period - for ten years instead of five - had a lower risk of recurrence and breast cancer mortality.

The ASCO conference also heard that 62% of young women in a US study opted to have either a single or double mastectomy rather than a surgical procedure that would conserve the breast. This is despite previous research that found overall survival rates for lumpectomy followed by radiation compared with mastectomy are the same.



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