Locally Recurrent Rectal Cancer: Management and Follow-Up

Introduction

An estimated 40,000 new cases of rectal cancer were diagnosed in the United States in 2015, encompassing almost one third of all newly diagnosed colorectal cancers. In 4% to 19% of these patients, pelvic recurrence will develop after curative resection. These patients often experience significant pelvic pain, dysesthesia, tenesmus, and other local complications that severely impair quality of life. Early diagnosis and aggressive surgical treatment of locally recurrent rectal cancer may be justified in carefully selected patients and may possibly palliate these problems, as well as potentially prolong disease-free and overall survival.

Nomenclature of Pelvic Recurrence

Several classification systems have been used to describe pelvic recurrences. The most useful of these systems is an anatomic classification of recurrence because it facilitates discussion of possible treatment options and allows for meaningful comparisons of prognosis ( Fig. 32-1 ).

The anatomic classification of recurrence separates the pelvis into axial, anterior, posterior, and lateral regions. The axial region includes both mucosal and perirectal soft tissue recurrences, which may occur after a transanal or transsphincteric excision, at the anastomosis after a low anterior resection (LAR) with primary reconstruction, and in the mesorectum. Axial recurrences also include recurrence of disease in the perineum after an abdominoperineal resection (APR), although these recurrences are relatively rare. Anterior recurrences involve the genitourinary tract, including the vagina, uterus, urinary bladder, and/or distal ureters in women and the seminal vesicles, prostate, urinary bladder, and/or distal ureters in men. The sacrum and/or pelvis are involved in posterior pelvic recurrences; whereas lateral recurrences can invade into adjacent pelvic sidewall structures such as the iliac vessels, pelvic ureters, obturator lymph nodes, adjacent nerves, and muscle, as well as the bony pelvis. It is important to note that pelvic recurrences may often involve multiple anatomic regions, and the degree of involvement in each will dictate whether the patient is a candidate for radical salvage resection.

Clinical Evaluation for Suspected Pelvic Recurrence

Patients who have had surgery for rectal cancer are followed up clinically at regular intervals. Asymptomatic recurrences may be found by digital examination, with routine imaging, or upon endoscopy. Symptoms such as a change in bowel habits, rectal bleeding, pain, and obstipation may herald a local recurrence, which is likely to be more extensive than recurrences found incidentally. Vaginal bleeding or urinary symptoms may reflect involvement of the genitourinary tract, whereas perineal pain or a persistent perineal sinus after APR may reflect a perineal recurrence or disease involving the sacrum. Leg edema and/or sciatic pain are ominous symptoms and suggest extensive pelvic sidewall involvement.

Physical examination should include a thorough examination of the abdomen, including palpation for an enlarged liver or tumor mass. A digital rectal examination is essential for any patient who has had LAR or local excision because anastomotic recurrences may be palpable and the digital examination will provide information with regard to the size of the recurrence, its location relative to the upper part of the anorectal ring, and the degree of fixation to the luminal wall. This information may indicate involvement of surrounding pelvic structures. Endoscopy may help define the proximal margin of the recurrence, the extent of the luminal involvement, and the overall extent of disease. Examination of the groin and supraclavicular regions is required to exclude adenopathy. Assessment of neuromuscular function in the lower extremities can identify deficits resulting from peripheral nerve involvement by lateral tumor recurrence. In women, a bimanual pelvic examination may reveal disease involving the rectovaginal septum, vagina, uterus, and adnexal structures. The perineal region after APR also should be closely examined to detect tenderness, a mass, or a sinus/fistula. A pelvic examination in women after APR facilitates the detection and extent of disease involvement. In patients with pelvic recurrence for whom radical surgery is being considered, a complete colonoscopy should be performed preoperatively to rule out synchronous neoplasms.

Although the interpretation of endorectal ultrasound (ERUS) images is subjective, especially in patients who have already undergone a surgical procedure, ERUS can detect pelvic masses and enlarged lymph nodes and can be used for an ERUS-directed biopsy of masses. In addition, a transvaginal ultrasound may be used in female patients who have undergone APR.

Computed tomography (CT) with use of both intravenous and oral contrast material may be useful for the detection and staging of local recurrence, as well as distant metastases. Asymmetric thickening of the bowel wall, obliteration of peri-anastomotic fascial or fat planes, a presacral or lateral sidewall mass, or enlarged regional lymph nodes are evidence of local recurrence. However, both surgery and radiation may lead to fibrosis and linear streaks in the perirectal fat, an appearance indistinguishable from a true recurrence. Magnetic resonance imaging (MRI) adds further anatomic detail pertaining to the depth of tumor infiltration into the rectal wall and has a negative predictive value of 93% to 100% for tumor invasion into adjacent structures in cases of locally recurrent rectal cancer. This additional information may be useful in preoperative planning and assessing the extent of an en bloc resection necessary to achieve a curative resection.

Positron emission tomography with CT (PET-CT) is an imaging modality that combines both anatomic and metabolic information for detecting recurrent disease. PET utilizes the glucose analog 18F-fluorodeoxyglucose to distinguish postoperative fibrosis and radiation changes from hypermetabolic cancer cells. PET-CT may also identify distant metastases that preclude an attempt at curative resection. Although not typically used for surveillance after primary rectal cancer resection, PET-CT may be helpful in select cases when information from other examinations regarding local and distant recurrence is inconclusive.

Management of Pelvic Recurrence

Nineteen percent to 52% of local recurrences are confined to the pelvis and thus are amenable to potentially curative repeat resection. After the diagnosis of pelvic recurrence is confirmed, the disease presentation usually falls into one of four categories based on the presence of extrapelvic disease, resectability of the recurrence, and the presence of symptoms. During the course of therapy, it is important to be alert to changes in symptoms because progression may require an alteration in management. Patient age and comorbidities are also important considerations in formulating a treatment strategy.