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 ).




FIGURE 32-1


Regions of rectal cancer pelvic recurrence. Pelvic recurrence can be classified on the basis of the anatomic region(s) of the pelvis involved with disease. Axial recurrences can involve (1) the anastomosis, (2) the mesorectum or perirectal soft tissue, or (3) the perineum after abdominoperineal resection. Anterior recurrences involve the genitourinary (GU) tract including the bladder, vagina, uterus, seminal vesicles, and prostate. Posterior recurrences involve the sacrum and presacral fascia. Lateral recurrences (not shown) involve the soft tissues of the pelvic sidewall and the lateral bony pelvis.


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.


Category I: Asymptomatic Local and Distant Recurrence


Because curative options for patients with concomitant local and distant recurrences are few, treatment should be offered judiciously, particularly for young asymptomatic patients. A small, highly select group may benefit from resection of two sites of isolated disease (e.g., pelvis and lung or liver). Data supporting the efficacy of this approach in curing patients with recurrence are limited.


Category II: Symptomatic Local Recurrence in the Presence of Distant Disease


The goal in treating symptomatic local recurrence in the presence of distant unresectable metastases should be to minimize morbidity and maximize palliation. Treatment options for patients with rectal bleeding from a local recurrence include fulguration, radiation, combined modality therapy (CMT), or palliative resection. Radiation or CMT also may be effective for the palliative treatment of pain, neurologic symptoms, and symptoms related to mass effect. Safe palliative options for patients with bowel obstruction due to recurrence within 10 to 12 cm of the anal verge include fulguration, laser ablation, gastrointestinal bypass, diversion, and endoscopic stenting.


Category III: Unresectable, Isolated Local Recurrence


Treatment options for patients with isolated, unresectable pelvic recurrence who have not received large doses of external beam radiation include preoperative CMT. A trial of external beam radiation with radiosensitizing 5-fluorouracil–based chemotherapy may result in a response that allows resection with negative histologic margins. Limitations include entrapment of small bowel in the pelvis after the initial resection and compromise in luminal diameter with impending obstruction. In these persons, a diverting colostomy or ileostomy will prevent the development of clinical obstruction while the patient receives CMT.


Category IV: Resectable Isolated Local Recurrence


Surgical resection is the only curative option for patients with isolated pelvic recurrence. The likelihood of a successful resection and the surgical options available to these patients are dictated, in part, by their primary procedure and the region of the recurrence. Patients may benefit from preoperative therapy in the form of radiation, chemotherapy, or CMT as a way of achieving an R0 resection (generally defined as complete resection with negative microscopic margins), which is associated with long-term local control.


Endoscopic stenting for stenosing recurrent rectal cancer may be considered as a temporary “bridging” approach for the facilitation of bowel preparation. However, if the stent remains in situ for a long time it may migrate distally, leading to worsening tenesmus and pain. Patients with a near-obstructing recurrence are at significant risk for progression to complete obstruction as a result of the initial swelling and edema that occur with external beam radiation and thus may benefit from a “bridging stent” or diverting ostomy before radiation treatment begins.


Cystoscopy with bilateral ureteric stent placement is recommended for all patients about to undergo surgery for a pelvic recurrence, especially when bladder involvement is suspected. The operative approach begins with an exploratory laparotomy, at which time up to a third of cases will be found to be unresectable. If unresectable extrapelvic and/or locally recurrent disease is detected and confirmed upon frozen section testing, a diverting loop colostomy or ileostomy is an option in cases of impending obstruction.


Overall, 32% to 64% of patients with locally recurrent rectal cancer are able to undergo a curative R0 resection. Reported 5-year overall survival for patients undergoing R0 resection ranges from 30% to 72%, with median overall survival significantly higher than for persons who undergo noncurative resections (7.1 vs. 1.9 years).


Axial Recurrences


Axial recurrences may represent a failure to obtain adequate distal margins during LAR, tumor implantation into the mesorectum during local excision, or perineal tumor implantation during APR. Sphincter preservation may be an option for high axial-anastomotic recurrences. However, the quality of life of persons undergoing a resection of locally recurrent disease with sphincter preservation may be diminished. Furthermore, significant lateral extension often requires a combined abdominal-perineal approach to ensure negative circumferential resection margins. Although wide local excision of a perineal soft tissue recurrence after APR may render the patient free of disease, the perineal recurrence is often a harbinger of disease deeper in the pelvis, which would require a combined abdominal-perineal approach to ensure a curative R0 resection. Regardless of the extent of the surgery, it is important to avoid inadvertent injury to the small bowel and other surrounding structures. The outcome for patients with recurrent disease limited to the bowel wall is much better than for patients with disease involving other regions.


Anterior Recurrences


Recurrences involving the genitourinary tract require en bloc removal of involved pelvic viscera to achieve negative histologic margins. A posterior pelvic exenteration (i.e., an APR with total abdominal hysterectomy, bilateral salpingo-oophorectomy, and posterior vaginectomy) is indicated for anterior pelvic recurrence in women with isolated uterine/vaginal involvement but no bladder involvement. A partial cystectomy or total pelvic exenteration (TPE) is required when the tumor involves the bladder. In women who have undergone a hysterectomy, an anterior recurrence generally mandates a TPE because usually no tissue plane exists between the recurrence and the bladder. After cystectomy, urinary drainage is provided by either an ileal conduit or a continent pouch. Although resection of the anterior viscera may facilitate negative resection margins anteriorly, obliterated anatomic planes secondary to previous surgery (especially APR) and radiation may limit the ability to ensure negative posterior and lateral resection margins. For this reason, whenever possible, the initial surgical approach should be in an unoperated plane where it has not been violated by previous surgery.


Pelvic exenteration is a technically challenging procedure with significant morbidity and should not be attempted unless a curative R0 resection is anticipated. Complication rates after TPE range from 37% to 100%, with an in-house hospital mortality rate of 0% to 25%. However, more recent studies suggest that perioperative mortalities can be as low as 0% to 5.5%. In carefully selected patients, curative pelvic exenteration may be associated with a 3-year local repeat recurrence rate of 40% to 60%, a 3-year disease-free survival rate of 22% to 57%, and a 3-year overall survival rate of 32% to 79% with a median survival of 2.4 years (some investigators report a disease-specific survival rate as long as 4 years).


Posterior Recurrences


In select posterior recurrences where sacral invasion is limited to the presacral fascia or superficial periosteum, an en bloc resection by periosteal elevation may achieve negative margins. When bony invasion of the sacrum is present, R0 resection can still be achieved using a combined abdominal-sacral resection. A sacrectomy may be performed in combination with an APR or pelvic exenteration depending on the extent of pelvic disease. Such resections usually entail a lengthy operation with significant blood loss. The most potentially morbid aspect of an abdominal-sacral resection is the bony transection, which involves a significant risk of hemorrhage and sacral nerve root damage. Major morbidities associated with this procedure include intestinal and urinary fistula, wound complications, pulmonary embolus, and bladder dysfunction.


Bladder dysfunction is related to the level of sacral transection. Sacral transection below S3 does not usually affect urinary continence, but mild urinary dysfunction occurs with unilateral division of S2 or S1. Bladder dysfunction occurs when both S2 nerve roots are resected and complete bladder denervation occurs after bilateral division of the S1 nerve roots. The feasibility and safety of sacral resection has been demonstrated by several centers, with a reported in-hospital mortality of 0% to 3%.


Lateral Recurrences


Recurrences along the pelvic sidewall are the least likely to be salvaged by resection. These tumors often adhere to the bony pelvis and/or invade the sciatic nerve. Patients may present with disabling pain radiating to the buttocks, perineum, and posterior thighs. Ureteral obstruction due to recurrent disease is also associated with a low likelihood of R0 resection. Iliac nodal disease can be removed en bloc with a local soft tissue resection that may involve a partial ureterectomy and partial resection of major arteries and veins.

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Jul 15, 2019 | Posted by in GENERAL | Comments Off on Locally Recurrent Rectal Cancer: Management and Follow-Up
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