Radiation Therapy

I've discussed the trials that have led to a general recommendation in favor of chemotherapy after surgery for patients who have stage II and IIIA NSCLC, with some ongoing questions about the value in stage IB NSCLC. I haven't touched the issue of post-operative radiation therapy, but the question comes up from members who ask about the evidence for or against radiation, and how it might be given.

Several people have asked about the technique of radiofrequency ablation, or RFA, for lung tumors. RFA is a pretty specialized approach in which a needle probe is inserted through the skin, under visual guidance using a CT or ultrasound, to go directly into a tumor. The tip is then pushed out and splays into a shape like the frame of an umbrella, and then an electric current is turned on to superheat the tip of the probe. In some cases, the probe is moved around to cover a broader area and destroy a larger tumor, but the procedure works particularly well for smaller tumors.

We've established that bone metastases are common, and now we'll talk about approaches to manage pain that often accompanies them. As I mentioned previously, sometimes a metastases occurs in a weight-bearing bone, in which case we often recommend a prophylactic surgical procedure to stabilize the bone at risk for fracture. Radiation can also reduce the risk for fracture and improve pain.

For patients with locally advanced NSCLC, the question of whether to pursue a surgical or a non-surgical approach has a great deal to do with the extent of mediastinal (middle of the chest) lymph node involvement. The mediastinal nodes are shown here:

As I described in a prior post, pre-operative chemo and radiation are one very reasonable, aggressive option for stage IIIA NSCLC, particularly if the mediastinal lymph nodes involved are not large and there is only a single lymph node area involved.

As I noted in prior posts on the subject of unresectable stage III NSCLC, there is a general consensus that overlapping chemo and radiation is associated with better cure rates for this stage of locally advanced NSCLC than doing one followed by the other. At the same time, however, the overlapping, or concurrent chemo and radiation approach is associated with more challenges in terms of side effects, particularly esophagitis, as well as greater drops in blood counts, and potentially more inflammation in the lungs, or pneumonitis.

The oral EGFR inhibitors Iressa and Tarceva both have activity in advanced NSCLC, with proven responses in a minority of patients and improvements in cancer-related symptoms as well.

Prophylactic cranial irradiation, or PCI, for SCLC, usually limited disease (LD-SCLC), remains a controversial issue, although this is generally recommended for patients with LD-SCLC who have a complete response to treatment (no evidence of disease). However, the idea of radiating the brain of someone who has no evidence of cancer there and may never get it is something that many patients and also some oncologists (radiation oncologists and medical oncologists) may not embrace.

While SCLC accounts for only about 13% of lung cancer, and only approximately one third of patients with SCLC have limited disease SCLC (LD-SCLC), this remains a high stakes area with the potential for being cured, so it needs to be treated as optimally as possible. I'm going to give a brief history and highlight some of the current principles of what has developed as the current standard of care.

After several weeks of posts on other aspects of lung cancer, I am long overdue to write on small cell lung cancer (SCLC). Although it is good to see the number of SCLC cases decreasing over time, and becoming a smaller and smaller percentage of lung cancer cases overall (only about 13% in the US and steadily falling), this has translated into fewer clinical trials and less of a focus on SCLC in the lung cancer community. However, there are some promising developments that may lead to some long overdue progress in the field.