The goal of frequent follow-up in patients with a history of cancer has been to detect early recurrence of cancer, allowing institution of chemotherapy or radiation therapy to improve the chance of survival. However, no data are available to suggest that follow-up testing of patients who achieve clinical remission after treatment for small-cell lung carcinoma has an impact on the natural history of this disease. Perez and colleagues studied the value of screening procedures in patients who were enrolled in one of several Phase III clinical trials through the North Central Cancer Treatment Group (NCCTG).
The trials included patients with limited and extensive small-cell lung cancer. All had achieved a complete clinical response and were considered to be in remission from their original cancer. The follow-up protocol for these patients included a clinical history, physical examination, hematologic studies, chemistry studies and chest radiographs every four months for the first year and every six months thereafter.
A total of 1,044 patients originally were enrolled in the NCCTG studies, of whom 276 achieved clinical remission initially but subsequently had cancer recurrence. The authors attempted to obtain a random sample of 150 of these patients but ultimately were left with only 115 patients who could be appropriately included in the study. About 55 percent were men, and the median age was 62 years.
Cancer recurred within the first year after treatment in 49 percent of the study subjects. It occurred by the second follow-up year in 44 percent. In the remaining 7 percent, cancer recurred more than two years after the initial diagnosis. The median time until progression was 322 days in the 57 patients with extensive disease at the time of diagnosis and 443 days in those with limited disease.
The most common site of recurrence was the lung/pleura (44 percent of patients), followed by the lymph nodes (30 percent), the liver (26 percent) and the brain (22 percent). Disease recurrence was signaled by the clinical history alone in 71 percent of patients. Symptoms included headache, abdominal pain, bone pain, emesis and dyspnea. Physical examination uncovered disease recurrence in another 10 percent of patients who were without symptoms but were found to have hepatomegaly or lymphadenopathy. In the remaining patients, recurrence of cancer was found by chest radiography in 12 percent and by chemistry evaluations in 6 percent. Hematologic studies were never the sole indicator of disease recurrence.
In patients whose symptoms signaled recurrent cancer, 59 percent were seen at a time other than the scheduled four- or six-month interval appointment. Recurrence was detected at a scheduled visit in only 41 percent. All 115 patients died after recurrence of small-cell cancer. The duration of survival after recurrence ranged from one day to 793 days.
The authors conclude that the clinical history and physical examination are the best ways to detect recurrence of lung cancer. Since 12 percent of patients were diagnosed by follow-up chest radiographs, they believe it is reasonable to continue this practice. However, blood tests were not helpful in detecting recurrent disease, and the authors believe that blood tests could be omitted from follow-up protocols. They also state that while some patients may respond to a second regimen of chemotherapy, no satisfactory evidence indicates that instituting cytotoxic drug therapy early, before the development of symptoms, will improve the patient's quality of life or length of survival.