New Molecular Imaging Test to Improve Lung Cancer Diagnosis

Panitumumab, a humanized antibody used in cancer treatment, targets the epidermal growth factor receptor (EGFR), which is present on the surface of many cancer cells. This receptor is especially abundant in non-small-cell lung cancer, making it a prime target for anti-cancer therapies. Copper-64, a radioactive isotope, is used in positron emission tomography (PET) scans. Now, by combining panitumumab with copper-64, researchers and clinicians can more accurately locate and track tumors and better monitor the effectiveness of treatments.

A team of researchers from the University of Alberta (Edmonton, Canada) has developed a new molecular imaging technique that could improve the detection of lung cancer and offer enhanced monitoring of treatment progress. By pairing panitumumab with copper-64, this new method combines the antibody's precision targeting capability with the exceptional sensitivity of radioisotope detection, providing a tool for earlier and more accurate detection of lung cancer, as well as monitoring treatment responses. Copper-64, when linked to panitumumab, enables clinicians and researchers to track the "metabolic fate" of the antibody, including its accumulation and retention in cancer cells. To evaluate this imaging agent, the team used several preclinical lung cancer models in mice, including a metastasis model to identify lung cancer lesions in distant organs such as the liver. The study, published in Molecular Pharmaceutics, revealed that this imaging technique not only highlights tumors in the lungs but also identifies metastatic tumors in the liver.

This dual capability of detecting both primary and metastatic tumors while providing crucial molecular data about the cancer cells overcomes significant limitations of traditional diagnostic imaging techniques. For example, CT scans often miss smaller tumors or those located in challenging areas like soft tissues, and they do not offer molecular insights into cancer cells. The new PET imaging test can also serve as a valuable tool for tracking cancer growth and metastasis over time. The research team plans to explore further the combination of panitumumab with copper-67, a complementary isotope that can deliver targeted radiation to kill cancer cells. When paired together, panitumumab and copper-67 could locate and destroy cancerous cells while sparing surrounding healthy tissues. The researchers also suggest that other antibody therapies could be combined with radioisotopes, such as copper-64 and copper-67, to improve the detection and treatment of cancer, ultimately advancing patient care and outcomes.

“Instead of exposing the patient to an invasive biopsy, they can go and get an injection, and then we can use a PET scan to help see the tumor and help physicians to determine the best course of therapy,” said study co-author Afsaneh Lavasanifar.

“With our tools, imaging biomarkers like radiolabeled panitumumab and non-invasive PET imaging technology, we can provide valuable information to clinicians about the molecular footprint of cancer cells,” added Frank Wuest, oncology professor in the Faculty of Medicine & Dentistry.