How old were you when you knew you wanted to go into medicine? How did you arrive at a career in radiation oncology?
I wanted to work in medicine for as long as I can remember. I wanted to directly help patients and maintain a long-term relationship with them throughout their treatment and later their survivorship. I wanted to find a field of medicine that would allow me to perform active interventions to ease the burden of patients’ diseases. I am also passionate about research, which allows me to help more patients than just those who I can directly see in clinic and treat. Radiation oncology is the field of medicine that brought all of these things together – from daily treatments to long-term follow-up to procedures and interventions, and it is also one of the most data-driven fields in all of medicine.
Who is most susceptible to lung cancer? And what’s the best way to ensure early diagnosis?
Approximately 80% of all lung cancer deaths are caused directly by smoking, and the number is even higher when considering other factors like secondhand smoke. Thus, the most mitigating factor is to either never smoke or to stop smoking if you do.
There has been an increase in the proportion of lung cancers among patients who have never smoked. I believe that this can be explained by two things: the anti-smoking campaigns from the 1980s and 90s, which led to a reduction in the incidence of smoking-related cancers, as well as increased exposures to chemicals, carcinogens, pollution and, historically, radon. More investigation into this group of patients is needed, as non-smoking lung cancer used to make up less than 10% of lung cancer cases, but that number is now closer to 15%, and this is a patient group that we need to understand further.
Lung cancer is best detected early, where cure rates are much higher. Screening is very effective in people who meet the current recommendations, which are adults ages 50-80 with a 20 pack-year history of smoking, including both current smokers and those who quit within the past 15 years. This population should get annual low dose CT scans since lung cancer is difficult to treat in more advanced stages and 57% of patients are diagnosed with Stage 4 disease.
Why is proton therapy more effective in treating lung cancer than conventional radiotherapy?
Proton therapy is an effective treatment for all thoracic malignancies, including non-small cell lung cancer, small cell lung cancer, mesothelioma, thymic malignancies and thoracic sarcomas, and it is most helpful when the cancer has not spread outside of the chest. Proton therapy exposes much less normal tissues to radiation, which allows for fewer side effects and better preservation of quality of life compared to other treatments. Proton therapy can also treat tumors to higher radiation doses more safely, allowing for select patients to have improvements in tumor control and overall survival relative to traditional radiation therapy.
There are also biological aspects of proton therapy that make protons more effective at actually killing the tumor and engaging the immune system to attack cancer cells.
Talk about reirradiation. Why is it important to know that proton therapy can retreat a tumor that already received radiation?
One of the most important benefits to proton therapy is the ability to retreat a cancer that has received prior radiation. Approximately 30-50% of patients with lung cancer develop tumor progression at the site of prior radiation therapy, and 25% develop isolated local failure, meaning the recurrence is located where the primary tumor was and nowhere else. These patients are potentially curable with more local therapy, but typically they cannot safely receive more traditional radiation or any surgery. Proton therapy is often a safe and highly effective treatment option for these patients.
For patients who already received high doses of radiation with their first course of treatment, we can safely deliver targeted proton therapy and provide patients with a new chance of cure.
How is research advancing the evidence for proton therapy as a treatment for lung cancer?
I remain passionate about improving the outcomes for patients through research and am excited to advance our field through impactful clinical studies led by the New York Proton Center or performed in collaboration with colleagues at other institutions. Studies for lung cancer, and for other malignancies as well, are investigating different treatment regimens that could shorten treatment, making it more convenient for patients while also more effective at killing cancer. I am one of the national leads conducting a large phase III randomized trial determining which patients with lung cancer are most likely to have better survival and fewer toxicities when treated with proton therapy compared with traditional radiation therapy. And we are leading practice-changing reirradiation trials for patients with recurrences of their thoracic malignancies.
Proton therapy is still a scarce resource, as there are only 38 proton therapy centers in the United States. There is already strong evidence to date of its treatment benefits, but we need more definitive, larger studies to continue to legitimize proton therapy in the oncology community and with insurance companies, which would allow for increased accessibility of this advanced treatment modality to a broader group of patients.
Dr. Charles B. Simone, II is the Chief Medical Officer of the New York Proton Center. He is an internationally recognized expert in the use of proton therapy for thoracic malignancies and reirradiation and has an extensive background in traditional radiotherapy. Dr. Simone is a Full Member in the Department of Radiation Oncology at Memorial Sloan Kettering Cancer Center.