J Am Coll Surg 2000 Nov;191(5):511-8
Can postoperative surveillance with serial CEA immunoscintigraphy detect
resectable rectal cancer recurrence and potentially improve tumor-free survival?
Lechner P, Lind P, Goldenberg DM.
BACKGROUND: This study was performed to determine if postoperative serial
monitoring of rectal cancer patients can be performed with an
immunoscintigraphic imaging test for carcinoembryonic antigen (CEA). It was also
of interest to assess whether this test, in combination with standard monitoring
procedures used in an intensive surveillance plan, can result in the
identification of surgically salvageable patients. STUDY DESIGN: Forty
consecutive resected Dukes' B and C rectal cancer patients underwent a
prospective, single-institution, surveillance trial of physical examination
(including digital rectal examination), endoscopy, CT of the abdomen and pelvis,
liver ultrasound, chest x-ray, blood CEA, and CEA immunoscintigraphy with
arcitumomab (CEA-Scan, Immunomedics, Morris Plains, NJ) every 6 months for the
first 2 years and every 12 months for the next 3 years after initial operation.
Outcomes were compared with those from a similar group of 69 patients treated
previously at the same institution but without CEA imaging. RESULTS: A total of
219 CEA imaging studies were performed without any significant adverse effects
or immune responses, and resulted in lesion sensitivity, specificity, accuracy,
and positive and negative predictive values of 94.1%, 97.5%, 97.3%, 76.2%, and
99.5%, respectively. Of the 40 patients, 16 developed 22 surgically confirmed
local or distant recurrences, and CEA imaging correctly disclosed 82% of these
lesions pre-operatively. All of the patients found to have recurrences had at
least one tumor site by CEA imaging; only 6 of 16 had elevated blood CEA titers.
On a patient-basis, there was a sensitivity of 100%, a specificity of 79.2%, an
accuracy of 87.5%, and positive and negative predictive values of 76.2% and
100%, respectively. The potential therapeutic benefit of serial arcitumomab
imaging is suggested by the fact that 6 of 16 patients (37.5%) with recurrence
underwent potentially curative second-look operations, compared with 6 of 69
(8.7%) of a comparable population studied at this institution during an earlier
6-year period, using all of the same tests except CEA imaging. None of the
patients in this historic control group survived more than 21 months, although
the mean survival of the six patients resected for cure in the study population
was 35 months (range 11 to 69 months). During 6 years of followup, three of the
six re-resected patients eventually died of cancer recurrence, two died from
other causes (and were confirmed by necropsy to be tumor-free), and one patient
is still free of disease in the sixth year. CEA scanning appeared to be more
predictive of recurrence than blood CEA testing or other diagnostic modalities.
CONCLUSIONS: Arcitumomab inclusion in intensive surveillance of patients with
resected rectal cancer can disclose tumor recurrence at a stage that allowed
surgical salvage therapy in 37.5% of the 16 patients with recurrence who had
second-look surgery, and in 19% the patients were free of disease during
longterm followup. This pilot study suggests that a randomized prospective trial
comparing standard surveillance procedures to the use of CEA imaging added
thereto should be undertaken.
