National Cancer Centre Singapore’s Clinical Assistant Professor Stephanie Saw explains the advancements in treatment options that improve outcomes for patients diagnosed with early-stage lung cancer
Did you know that lung cancer is the leading cause of cancer-related deaths in Singapore? This is because lung cancer is usually diagnosed at an advanced stage, where the chance of long-term cure is low.
Early detection of lung cancer is difficult because there may not be any specific symptoms. General symptoms such as coughing and weight loss may also be dismissed or not deemed serious enough to warrant medical attention.
This is why many patients are only diagnosed at an advanced stage, when the cancer cells have spread to other parts of the body. According to the Singapore Cancer Registry Annual Report 2019, more than 60 per cent of patients with lung cancer are diagnosed at stage 4.
As such, taking the first step to get screened or seek a doctor’s advice on any symptoms or health concerns is important, since treatment recommendations vary and depend on the stage of the cancer and health status of each person.
Early detection of lung cancer improves cure rates. New clinical trial data suggests that adjuvant immunotherapy given after curative surgery may help to lower the risk of cancer recurrence in some patients.
Clinical Assistant Professor Stephanie Saw, a consultant in the Division of Medical Oncology at the National Cancer Centre Singapore, answers questions about lung cancer treatment and what can be done to help patients achieve better outcomes.
Q: What are the current treatment options and approaches for early-stage lung cancer?
The main treatment for early-stage lung cancer is surgery to remove part of or the entire lung where the cancer cells are located. After surgery, patients may be given further treatment to reduce the risk of cancer recurrence (adjuvant treatment). In some situations, treatment may be given before surgery to reduce the risk of the cancer spreading (neoadjuvant treatment).
For patients who are not eligible for surgery, radiation therapy can be considered.
Q: What is immunotherapy and how does it work for early-stage lung cancer?
Immunotherapy is a type of cancer treatment that aims to boost the immune system’s ability to defend the body against the disease. The immune cells are activated to better recognise cancer cells as foreign cells and destroy them. Adjuvant immunotherapy for early-stage lung cancer has been studied in two large clinical trials.
Atezolizumab, which targets a protein (PD-L1) expressed on tumour cells, given for one year, has been shown to reduce the risk of cancer recurrence or death by 34 per cent in patients with stage 2 and 3A lung cancer that have a PD-L1 score of 1 per cent or more after surgery and adjuvant chemotherapy. Recent updates showed improved overall survival among patients with a high PD-L1 score of 50 per cent or more. Consequently, adjuvant atezolizumab has recently been approved for this group of patients in Singapore.
Pembrolizumab, which targets a protein (PD-1) expressed on immune cells, given for 1 year, has demonstrated improved disease-free survival among patients with stage 1B, 2 and 3A lung cancer after surgery. The long-term survival data for this trial is currently pending.
Q: What are other systemic treatments for early-stage lung cancer?
Systemic treatments, or treatments that affect the whole body, include chemotherapy, immunotherapy and targeted therapy.
Some patients may require more than one treatment modality depending on factors such as the cancer stage. Adjuvant chemotherapy for early-stage lung cancer generally comprises two intravenous medicines, given after surgery for four cycles over three months.
Epidermal growth factor receptor (EGFR) is a protein on the cell surface that sends signals to the cell to grow. A mutation in the EGFR gene encourages abnormal cell growth, which can cause cancer. For patients with early-stage EGFR-mutated lung cancer, oral targeted therapies (tyrosine kinase inhibitors) can also reduce the risk of recurrence after surgery.
A combination of chemotherapy and immunotherapy in certain types of lung cancer before surgery may improve outcomes, although long-term survival data is pending.
Q: How can the outcomes of lung cancer patients be improved?
Consulting a doctor when unwell or experiencing symptoms such as prolonged coughing, shortness of breath, fatigue and unexplained weight loss is still key to early detection and treatment of lung cancer.
Cancer research aims to improve the ways cancer is diagnosed, treated and prevented. Clinical trials may allow eligible patients access to new lung cancer treatments before they are widely available.
The first local lung cancer screening study, SingapOre Lung cancer Screening Through Integrating CT with other biomarkErs (SOLSTICE), using Low-Dose Computed Tomography (LDCT), a screening test to detect pre- or early lung cancer, will be piloted on the Singapore General Hospital Campus and begin enrolment in 2023. It aims to recruit both smoking and at-risk non-smoking participants. More information will be available on National Cancer Centre Singapore's website and social media channels soon.