New ASTRO lung cancer guidelines reject RT + chemo
As part of an effort to clarify variable radiotherapy (RT) and chemotherapy treatment regimens, the American Society for Radiation Oncology (ASTRO) has published a series of guidelines for lung cancer treatment, notably concluding that the literature does not support chemotherapy treatment concurrent with palliative RT.

In 2009, ASTRO convened a task force of 11 (radiation) oncology physicians to perform a systematic review of literature to answer three topical questions relating to lung cancer treatment:

  • What is the optimal dose/fractionation schedule for thoracic palliative external beam RT in patients with lung cancer?
  • What is the role of endobronchial brachytherapy alone or in conjunction with other modalities (including external beam RT) in both the initial and salvage palliative management of lung cancer?
  • What is the role of chemotherapy administered concurrently with radiation for the palliation of lung cancer?
The aim of the guidelines was, “To provide guidance to physicians and patients with regard to the use of external beam radiotherapy, endobronchial brachytherapy and concurrent chemotherapy in the setting of palliative thoracic treatment for lung cancer, based on available evidence complemented by expert opinion,” explained George Rodrigues MD, from the department of radiation oncology at London Health Sciences Centre in London, Ontario, and colleagues.

Relying in part on the review of the Cochrane Collaboration, Rodrigues and co-authors evaluated 14 randomized controlled trials and determined that external beam RT can alleviate thoracic symptoms in patients with locally advanced or metastatic non-small cell lung cancer (NSCLC) who are not eligible for curative therapy.

Moreover, Rodrigues and colleagues concluded that higher doses are associated with “modest improvements” in patient survival and symptoms, mainly among patients with good performance statuses. The authors recommended external beam RT regimens around 30 Gy with 10 fractions, while also offering alternatives approximated at five fractions of 20 Gy or two weekly fractions of 17 Gy, both proposed to reduce the procedure’s side effects.

“There is currently no randomized or metaanalysis-based evidence to recommend [endobronchial brachytherapy] alone or in conjunction with other palliative therapies ([external beam] RT, chemotherapy, Nd:YAG laser) in the routine initial palliative management of endobronchial obstruction resulting from lung cancer,” the task force concluded.

Rodrigues and colleagues did note, however, that if central endobronchial disease has already caused a collapsed lung, studies indicate that initial endobronchial brachytherapy in conjunction with external beam RT could be considered. In addition, endobronchial brachytherapy serves as a “reasonable option” for palliative management of patients with endobronchial lesions that cause obstruction or hemoptysis and who have already undergone external beam RT.

The task force added, “Continuing prospective clinical trials in the areas of initial and salvage [endobronchial brachytherapy] are encouraged to better define the role of this modality in the palliation of [lung cancer] patients.”

Finally, the task force stated, “At this time, there is no added benefit for the use of chemotherapy concurrently with radiation therapy (RT) in the palliation of thoracic symptoms in lung cancer patients.”

The authors cited one phase III study that had directly addressed this question. Although the trial found that the addition of chemotherapy to RT did improve responses, “this small benefit came at the cost of significant increased toxicity with no significant improvement in overall survival, progression-free survival or symptom palliation.”

“The use of concurrent chemoradiation should primarily be reserved for clinical trials,” the task force concluded.

Published in the April-June issue of Practical Radiation Oncology, the ASTRO Task Force guidelines can be read here.