Cancer research trials take many years to complete. Below are some of our most significant achievements relating to completed trials.
The landmark TROG 03.05 MA.20 trial showed that radiation treatment of the lymph nodes in addition to the breast after breast cancer surgery can prolong the time women remain cancer-free. For more than 10 years researchers monitored 1,832 women with breast cancer that had spread to the lymph nodes; 82% of the women who received radiation to the breast and lymph nodes were free of cancer, compared to 77% of women who received radiation to the breast only. This large international trial has shown that lymph node radiation not only reduced the likelihood of cancer coming back in the lymph nodes ten years later, it also decreased the risk of cancer coming back in the other parts of the body, such as the liver and lungs, from 17.6% to 13.7%.
The TROG 96.01 trial showed that the chances of cancer returning in the prostate could be reduced by approximately 60% using a course of hormone therapy prior to radiotherapy. The study also showed that the treatment with hormone therapy substantially reduced the chances of cancer appearing in other parts of the body, which could otherwise prove fatal. This trial involved more than 800 men with inoperable prostate cancer. Long term follow up of these men continues.
The TROG 03.04 RADAR trial enrolled more than 1,000 men with newly-diagnosed aggressive but localised prostate cancer using testosterone suppression therapy, radiotherapy as well as a different type of anti-cancer drug. This research gave men with newly-diagnosed cancer a better chance of survival without increased long term side effects.
The TROG 03.06 TOAD trial, was conducted to determine if immediate intervention with androgen deprivation therapy (ADT) would improve overall survival, compared with delayed ADT in prostate cancer patients with a rising prostate specific antigen (PSA). Researchers discovered that men with incurable prostate cancer, but without symptoms, who received immediate hormone treatment had an increase in survival over those who delayed treatment. The results show that 80% of patients were still alive after six years, compared to 65% of men for whom treatment was delayed until they showed further symptoms or signs of progression.
The TROG 96.06 trial showed that the risk of skin cancer recurring following lymph node surgery for melanoma could be dramatically reduced with a course of radiotherapy following surgery. The study was conducted over 11 years involving more than 200 patients recruited from seven cancer centres in Australia and New Zealand. This study showed that the chance of skin cancer reappearing was reduced by approximately 30% with the addition of radiotherapy following the standard surgical treatment. The trial was based on results of TROG 96.06 study and also supported the results in favour of surgery plus radiotherapy.
Head & neck cancer
The TROG 07.03 RadioHum trial evaluated the impact of humidification on mucositis in patients treated for head and neck cancer. Although it did not demonstrate a significant difference between the mucositis experienced by the two groups, the results show that humidification can play a role in reducing symptoms during radiotherapy for head and neck cancer. On average, patients who received humidification spent 57% as many days in the hospital to manage side effects. The return of eating patterns to close to normal was also significantly higher at three months after radiotherapy in the group using humidifiers. The secondary analyses are currently underway.
The TROG 03.07 trial compared two chemotherapy regimens combined with radiotherapy for stage three and stage four non small cell lung cancer in patients not suitable for surgery. The trial showed a positive result in favour of the arm of the trial where a chemotherapy drug called vinorelbine was used.
The TROG 89.04 trial showed that the five year survival outlook could be improved by up to five times using a treatment of concurrent radiotherapy and chemotherapy, compared to the standard treatments of either surgery or radiotherapy alone, which had a five year survival outlook of 5% to 10%.
The TROG 03.01 trial was the largest randomised phase three trial in advanced oesophageal cancer and was a significant undertaking for a 'palliative care' trial, namely where the emphasis was on the best yet simplest and least toxic treatment. The research showed that radiation therapy alone is as effective in decreasing swallowing complications experienced by advanced esophageal cancer patients as radiotherapy combined with chemotherapy, thus allowing patients to forgo chemotherapy.
The Canadian-based international TROG 03.08 BONEMETS trial involving 850 patients (114 from TROG) compared a single large dose of radiation with 5 (or 8) smaller doses for patients with bone metastases (secondaries) previously treated at the same site with radiotherapy. Pain was improved in about half of the patients with either schedule, although there were fewer side effects with the single dose option. Patients who responded to the re-irradiation had improved quality of life.
Neuropathic pain due to bone metastases occurs when cancer has spread to bone and irritates or compresses nearby nerves. The TROG 96.05 trial found that five smaller doses of radiotherapy delivered over five days are slightly more effective than one larger dose delivered on one day.
The TROG 03.02 trial was launched to test the feasibility of a novel chemoradiation regimen for gastric cancer, which concluded that: chemoradiation was feasible and could be safely delivered in a cooperative group setting. The three year survival rate of 61.6% was encouraging, given that many centres were implementing this treatment for the first time.
The TROG 99.04 trial, which looked at chemotherapy and radiotherapy as a treatment for Osteolymphoma (OL), showed a relatively high rate of local and distant disease control, as well as a low rate of toxicity. It remains the only prospective trial addressing this particular disease and it has provided TROG with valuable experience in the testing of rare diseases.
Quality assurance for radiotherapy doses
A quality assurance study conducted by TROG showed that the radiotherapy dose delivered by 18 radiotherapy centres in Australia and New Zealand was strictly as intended, confirming the accuracy and standardisation of equipment and procedures. The study used a mock patient (nicknamed 'Elvis) made from plastics of varying densities to mimic the human anatomy. The study provided reassurance to the oncology community and the general public that all participating centres were able to deliver the prescribed dose to the target volume of the anatomy.