Surgery is the leading therapy for GIST . Currently, LE and RE are feasible surgical strategies for rectal GIST . RE is associated with low local recurrence , but always results in large trauma, severe bowel dysfunction, and poor quality of life . LE is a minimal invasion method to preserve the function of anal sphincter , especially in the modern era of imatinib target therapy . Typically, LE is related to higher local recurrence and shorter survival time than RE.
Yasui et al. collected rectal GIST patients across 40 institutions from 2003 to 2007; however, only 24 cases were enrolled in the study due to the low incidence of this disease . The study found that the local recurrence rate was 30.4% after curative resection, but that did not differ after LE (33.3%) vs. extended resection (28.6%) . Shu et al. analyzed 71 rectal GIST patients from 2004 to 2017, including 42 patients who underwent LE and 29 patients who underwent RE, in a retrospective study. The study also showed that the two surgical approaches did not have any significant impact on recurrence-free survival . Interestingly, the patients who underwent LE have longer overall survival than RE, but the RE patients were more moderate-high risk malignancy cases than those undergoing LE . In addition, LE is a preferred surgery for rectal GIST with less injury and short hospital stay . Guo et al. also found that LE has a similar clinical prognosis with RE, and LE can achieve short operative time, less operative bleeding, and a quick recovery, especially when combined with neoadjuvant therapy of imatinib [6, 7]. However, the optimal surgical strategy for rectal GIST remains controversial due to the low incidence and limited patient scale [6, 14,15,16,17,18,19].
In this retrospective study, we analyzed 154 rectal GIST patients in the SEER database. Although the number of patients enrolled was also limited, to the best of our knowledge, this is the largest population-based study on rectal GIST.
We found significant differences in CSS time for rectal GIST patients with respect to age, tumor differentiation, and radiotherapy, indicating that rectal GIST patients aged ≤ 60 years, with well/moderate differentiation and undergoing radiotherapy, exhibit a prolonged CSS time. Historically, GIST is considered radiation-resistant, and radiotherapy is not the predominant treatment for GIST. However, recent studies showed that radiation might be beneficial in advanced-stage GIST [23, 24]. The current results showed that radiotherapy benefits rectal GIST patients with a better prognosis, implying that radiotherapy may be a promising and potential treatment for rectal GIST but needs further investigation. Intriguingly, no significant differences were observed in the CSS time with respect to gender, race, tumor size, T classification, N classification, and regional LN surgery. The results further confirmed that regional LN surgery is unnecessary . Imatinib is used as the first-line treatment for rectal GIST for a satisfactory oncological outcome . Also, no significant differences were noted in the CSS time of chemotherapy in this study, but the detailed information of chemotherapy was unavailable, which we thought greatly influenced the result.
The present study aimed to compare the long-term survival of rectal GIST patients who underwent either LE or RE. Our results did not detect any significant difference in the CSS time between the two surgeries with respect to age, gender, race, tumor differentiation, tumor size, T classification, N classification, regional LN surgery, chemotherapy, and radiotherapy. These results suggested that the two surgical procedures are similar in terms of survival outcomes and a limited excision range, i.e., LE might be sufficient for rectal GIST patients.
Although we analyzed a large number of rectal GIST patients in the public SEER database, the present study has certain limitations. First, it is a retrospective study, and thus, bias is inevitable. Second, the lack of information on the neoadjuvant or adjuvant therapy of imatinib, distance of the tumor from anal verge and mitotic figures of the tumor, which might influence the survival of patients. Third, the lack of information on postoperative recurrence and the quality of life of rectal GIST patients might affect the choice of surgical strategy of surgeons. Thus, high-quality randomized controlled trials (RCTs) are imperative to elucidate the significance of both surgical approaches. Nonetheless, future studies would focus on the postoperative life quality of patients to determine the optimal approach for rectal GIST.