Patients with very early stage colon cancer benefit as much from regular followup testing after surgery as later stage patients do.
While overall patients with stage I or IIA colon cancer (early stage) have a lower risk of cancer returning than patients with stage IIB or III (later stage), careful surveillance after surgery is as effective in finding and treating cancer in both groups.
About one in three patients in both the early and late stage who had a recurrence detected during surveillance were able to have surgery with the goal of curing their cancer.
Using information from the Clinical Outcomes of Surgical Therapy (COST) study, researchers divided 872 patients without metastatic colon cancer into two categories:
- Early stage disease: stages I or IIA
- Late stage disease: stages IIB and III
All patients in the study, no matter their stage at diagnosis, followed the same surveillance plan after surgery.
- History and physical exam every 3 months for 1 year then every 6 months to 5 years
- Carcinoembryonic antigen (CEA) blood test every 3 months for 1 year then every 6 months to 5 years
- Chest x-ray every 6 months for 2 years then every 1 year to 5 years
- Annual colonoscopy if positive for polyps or cancer; exam every 3 years if first one was negative
- CT scan of abdomen at discretion of physician for symptoms, signs, or increased CEA
- By five years, about 1 in 10 early stage patients had a recurrence of their cancer (9.5 percent) compared to about 1 in 3 late stage patients (35.7 percent).
- Sites where cancer had spread were similar in both groups, although late stage patients were more likely to have spread to more than one site.
- Median survival after surgery for recurrence, when possible, was 51.2 months for early stage and 35.8 months for late stage patients.
There was little difference between groups in how the recurrence was initially found:
- Elevated carcinoembryonic antigen (CEA) test found 29 percent of early versus 37 percent of late stage recurrent cancers and was the most common way of finding recurrences, particularly in the second year when it found more recurrences than CT-scan, chest x-ray, and colonoscopy combined.
- CT-scans uncovered 24 percent of early versus 26 percent of late stage recurrences.
- Chest x-rays found 7 percent of early versus 12 percent of late stage recurrence.
- Colonoscopy found 13 percent of early versus 9 percent of late ones.
Of the entire group of 537 patients with an early stage diagnosis (stage I and IIA), 55 had a recurrence. 20 of them went on to a second surgery and had a median survival of 51 months after their operation. Those for whom surgery wasn’t possible had a much shorter survival of about 9 months.
There were 254 patients initially diagnosed as late stage (stage IIB and III). Of those, 91 experienced a recurrence and 32 were able to have a second surgery. Like the early stage patients, a second surgery led to much longer survival — 36 months versus 11 months without surgery.
Vassiliki L. Tsikitis and the study team concluded,
Patients with early-stage colon cancer have similar sites of recurrence, and receive similar benefit from postrecurrence therapy as late-stage patients; implementation of surveillance guidelines for early-stage patients is appropriate.
SOURCE: Tsikitis et al., Journal of Clinical Oncology, Volume 27, Number 22, August 1, 2009.