Circulating Tumor Cells Useful in Early Assessment and Therapy Monitoring in Lung Cancer

The identification of targeted cancer biomarkers and precision medicine has improved cancer treatment considerably during the past few decades.¹ For patients with lung cancer, a number of tumor biomarkers have been identified.¹ However, obtaining an adequate tumor sample can limit the number of biomarkers that can be assessed.¹ In addition, tissue biopsy can be very invasive and may not show tumor heterogeneity.¹

To overcome some of the limitations of tissue biopsy, liquid biopsy can be a useful, minimally invasive tool to use when tissue samples are unattainable or inadequate in size.¹ Body fluids that can yield useful samples include blood, saliva, urine, effusions, and cerebrospinal fluid.¹ Liquid biopsy is also useful to track the development of therapy-resistant mutations.¹

Circulating tumor cells in patients with lung cancer were evaluated in a recent study. The investigators were interested in determining if circulating tumor cells could precisely indicate response to chemotherapy and if they could help provide early diagnostic information. The study included 56 patients who had a new diagnosis of lung cancer, 42 patients who had benign lung disease, and 27 healthy controls. Baseline circulating tumor cells were measured in all participants, and in 25 patients with advanced lung cancer they were measured after 2 rounds of chemotherapy.

In patients with lung cancer, the number of circulating tumor cells was significantly increased compared with the other 2 groups. The sensitivity of circulating tumor cells reached 87.5%, and specificity was 95.7%.

The patients with advanced lung cancer were followed for an average of 18.2 months. All patients with advanced lung cancer had disease progression, and 16 patients died during the study period. In this patient group, a change in circulating tumor-cell count after the 2 cycles of chemotherapy was highly predictive of progression-free survival and overall survival. Analysis of patients who had stable disease after 2 cycles of chemotherapy as indicated on computed tomography scan showed that patients who had a decrease in circulating tumor cells had significantly longer progression-free survival and overall survival compared with those who had an unchanged or increased posttreatment circulating tumor cell number.

Reference:

1. Sánchez-Herrero E, Serna-Blasco R, Robado de Lope L, González-Rumayor V, Romero A, Provencio M. Circulating tumor DNA as a cancer biomarker: an overview of biological features and factors that may impact on ctDNA analysis. Front Oncol. 2022;12:943253.

Source: Chen J, Li Q, Xu C, Qian Y, Yang Z, Chen D. Circulating tumor cells as a biomarker for precise management in lung cancer. J Clin Oncol. 2022;40(suppl 16):e21018.