Clinically enlarged lateral pelvic lymph nodes do not influence prognosis after neoadjuvant therapy and TME in stage III rectal cancer

Lateral lymph node involvement presents another challenge in rectum cancer in the age of neoadjuvant chemoradiotherapy + total mesorectal excision: an evaluation of survival outcomes

PURPOSE

In the last decades, total mesorectal excision (TME) and neoadjuvant chemoradiotherapy (nCRT) have produced an undeniable improvement in the treatment of rectal cancer. However, local recurrence is still an important problem, and the effect of lateral lymph node (LLN) involvement on local recurrence is a controversial issue. The aim of this study was to investigate the effects of LLN status on local recurrence and survival in rectal cancers treated with nCRT + TME.

METHODS

Clinical features, pre- and post-nCRT lateral pelvic region imaging, long-term local recurrence, and the survival outcomes of 114 patients who underwent nCRT + TME for rectal cancer were evaluated.

RESULTS

On MRI before nCRT, 20 (17.5%) patients had lateral lymph nodes (LLN+), and 94 (82.5%) patients had no lymph nodes in the lateral pelvic compartments (LLN-). Local recurrences at 1 year in LLN+ and LLN- patients were 3 (15.8%) and 2 (2.3%), respectively (p=0.039). Five-year local recurrence-free survival rates and the mean duration of recurrence-free survival in LLN+ and LLN- patients were 56.2%, 42.6 months, and 87.3% 66.9 months, respectively (p=0.001). Disease-free survival and overall survival were shorter in LLN+ patients, but the difference was not statistically significant (p=0.096 and p=0.46, respectively). In the multivariate analysis, LLN involvement was determined to be an independent risk factor for local recurrence-free survival (Hazard Ratio 4.54, p=0.003).

CONCLUSION

Lateral lymph node involvement causes local recurrence to remain high after nCRT + TME. LLN status should be considered in treatment planning. Further studies are needed to define precise criteria for LLN involvement and the effect of LLND on local recurrence and survival.

Positive lateral pelvic lymph nodes in low rectal cancer: should we change our practice now?

BACKGROUND

The role of lateral lymph node dissection (LLND) in the treatment of patients with low rectal cancer with enlarged lateral lymph nodes (LLN+) is under investigation. Enthusiasm for LLND stems from a perceived reduction in local recurrence (LR). We aimed to compare the LR rate for LLN+ patients with LLN- patients, treated with neoadjuvant chemoradiotherapy (nCRT) and surgery, in a hospital that does not perform LLND.

METHODS

A retrospective study of all patients with clinical stage 3 low rectal cancer who completed nCRT and surgery between 2008 and 2017 at Western Health was performed. Outcomes for LLN+ patients were compared with LLN- patients. The primary outcome was LR. Secondary outcomes included distant metastases, disease-free survival and overall survival.

RESULTS

There were 110 patients treated for stage 3 low rectal cancer over 10 years. There was no significant difference in the LR rate, with one LR from 28 LLN+ patients and one LR from 82 LLN- patients (4% versus 1.2%, P = 0.44). There were no significant differences in median disease-free survival (41 versus 52 months, P = 0.19) or mean overall survival (62 versus 60 months, P = 0.80). Of all patients studied, 21% developed distant metastases.

CONCLUSION

LR after nCRT and surgery in patients with stage 3 rectal cancer is rare, irrespective of lateral pelvic node status. These data, along with the uncertain benefit and known risks of LLND, supports the continued use of standard therapy in these patients. Strategies to address distant failure in these patients should be explored.

Management of synchronous lateral pelvic nodal metastasis in rectal cancer in the era of neoadjuvant chemoradiation: A systemic review

BACKGROUND

Lateral pelvic lymph node (LLN) metastasis (LLNM) occur in up to 28% of patients with low rectal tumours. While prophylactic lateral pelvic lymph node dissection (LLND) has been abandoned by most western institutions in the era of neoadjuvant chemoradiation therapy (CRT), the role of selective LLND in patients with enlarged LLN on pre-CRT imaging remains unclear. Some studies have shown improved survival and recurrence outcomes when LLNs show “response” to CRT. However, no management algorithm exists to differentiate treatment for “responders” vs “non-responders”.

AIM

To determine if selective LLND in patients with enlarged LLNs results in improved survival and recurrence outcomes.

METHODS

A systemic search of PubMed and Embase databases for studies reporting on patients with synchronous radiologically suspicious LLNM (s-LLNM) in rectal cancer receiving preoperative-CRT was performed.

RESULTS

Fifteen retrospective, single-centre studies were included. 793 patients with s-LLNM were evaluated: 456 underwent TME while 337 underwent TME with LLND post-CRT. In the TME group, local recurrence (LR) rates range from 12.5% to 36%. Five-year disease free survival (DFS) was 42% to 75%. In the TME with LLND group, LR rates were 0% to 6%. Five years DFS was 41.2% to 100%. Radiological response was seen in 58%. Pathologically positive LLN was found in up to 94% of non-responders vs 0% to 20% in responders. Young age, low tumour location and radiological non-response were associated with final positive LLNM and lowered DFS.

CONCLUSION

LLND is associated with local control in patients with s-LLNM. It can be performed in radiological non-responders given a large majority represent true LLNM. Its role in radiological responders should be considered in selected high risk patients.

Lateral Lymph Node Metastases in Locally Advanced Low Rectal Cancers May Not Be Treated Effectively With Neoadjuvant (Chemo)Radiotherapy Only

Background: In the West, pre-treatment abnormal lateral lymph nodes (LLN+) in patients with a low locally advanced rectal cancer (AJCC Stage III), are treated with neoadjuvant (chemo)radiotherapy (nCRT), without a lateral lymph node dissection (LLND). It has been suggested, however, that LLN+ patients have higher local recurrence (LR) rates than similarly staged patients with abnormal mesorectal lymph nodes only (LLN−), but no comparative data exist. Therefore, we conducted this international multi-center study in the Netherlands and Australia of Stage III rectal cancer patients with either LLN+ or LLN− to compare oncological outcomes from both groups.

Materials and Methods: Patients with Stage III low rectal cancer with (LLN+ group) or without (LLN− group) abnormal lateral lymph nodes on pre-treatment MRI were included. Patients underwent nCRT followed by rectal resection surgery with curative intent between 2009 and 2016 with a minimum follow-up of 2-years. No patient had a LLND. Propensity score matching corrected differences in baseline characteristics.

Results: Two hundred twenty-three patients could be included: 125 in the LLN+ group and 98 in the LLN− group. Between groups, there were significant differences in cT-stage and in the rate of adjuvant chemotherapy administered. Propensity score matching resulted in 54 patients in each group, with equal baseline characteristics. The 5-year LR rate in the LLN+ group was 11 vs. 2% in the LLN− group (P = 0.06) and disease-free survival (DFS) was 64 vs. 76%, respectively (P = 0.09). Five-year overall survival was similar between groups (73 vs. 80%, respectively; P = 0.90).

Conclusions: In Western patients with Stage III low rectal cancer, there is a trend toward worse LR rate and DFS rates in LLN+ patients compared to similarly staged LLN− patients. These results suggest that LLN+ patients may currently not be treated optimally with nCRT alone, and the addition of LLND requires further consideration.

Diagnostic and management strategies for lateral pelvic lymph nodes in low rectal cancer-a review of the evidence

Patients with low rectal cancer who have enlarged lateral pelvic lymph nodes are known to have a worse prognosis. There is however uncertainty over what constitutes a lateral pelvic lymph node of clinical significance. As the main modality for the detection of such lymph nodes is magnetic resonance imaging (MRI), characteristics of these lateral lymph nodes identified may have prognostic value and assist with guiding treatment. Options to manage such lateral lymph nodes includes neoadjuvant chemoradiotherapy as well as lateral lymph node dissection. Surgery is extensive and may lead to significant morbidity to the patient. This review article evaluates diagnostic and management strategies in patients with lateral pelvic lymph nodes in low rectal cancer.

Preoperative Chemoradiotherapy Might Improve the Prognosis of Patients with Locally Advanced Low Rectal Cancer and Lateral Pelvic Lymph Node Metastases

BACKGROUND

Preoperative chemoradiotherapy (CRT) is a standard treatment for locally advanced low rectal cancer (LALRC). However, the prognostic significance of CRT in patients with lateral lymph node metastasis (LLNM) is unknown. The present study aimed to examine the prognostic impact of preoperative CRT in patients with LALRC and LLNM.

METHODS

We retrospectively analyzed data for 73 patients with LALRC and LLNM who underwent total mesorectal excision and lateral lymph node dissection from 1985 to 2012. The patient population was divided into a CRT group (n = 30) who received preoperative CRT and a surgery alone group (n = 43) who were treated without CRT.

RESULTS

The 5-year overall survival (OS), 5-year relapse-free survival (RFS), and 5-year local recurrence (LR) rates were significantly better in the CRT group (78.2, 72.1, and 3.5 %, respectively) compared with the surgery alone group (41.1, 25.4, and 39.6 %, respectively). There were fewer total, mesorectal, and LLNMs in the CRT group compared with the surgery alone group. Multivariate analysis showed that surgery without CRT was an independent predictor of poorer OS (hazard ratio [HR] 3.513, p = 0.004), RFS (HR 2.696, p = 0.021), and LR rates (HR 11.094, p = 0.001). A total number of lymph node metastases ≥4 were also an independent predictor of poorer OS and RFS.

CONCLUSIONS

Preoperative CRT might have a significant prognostic impact on patients with LALRC with LLNM treated with total mesorectal excision and lateral lymph node dissection.

Clinical significance of enlarged lateral pelvic lymph nodes before and after preoperative chemoradiotherapy for rectal cancer

Preoperative chemoradiotherapy (CRT) with total mesorectal excision (TME) is the widely accepted treatment for rectal cancer (RC) in Western countries. However, there remains controversy as to whether preoperative CRT is useful in tumors that extend beyond the mesorectum, including metastasis to the lateral pelvic lymph nodes (LPLN). The aim of this study was to assess the prognostic significance of LPLN enlargement in patients with RC who receive preoperative CRT followed by TME without LPLN dissection. We evaluated the prognostic effect of radiographic LPLN enlargement before and after CRT, as well as the patients' clinicopathological and genetic profiles. Of the 104 patients investigated, pretreatment imaging identified 19 (18%) as LPLN-positive (>7 mm in diameter). Of these 19 patients, 7 (37%) exhibited LPLN downsizing to <7 mm following CRT. The median follow-up period was 52 months. The 5-year cancer-specific survival (CSS) or relapse-free survival (RFS) did not differ significantly between patients who did and those who did not have positive LPLN on pretreatment imaging. However, LPLN that remained positive after CRT were significantly associated with poorer 5-year CSS (73 vs. 84%, respectively; P=0.0052) and RFS (32 vs. 78%, respectively; P=0.0264). None of the patients whose LPLN were downsized to <7 mm following CRT developed recurrence; however, those with positive LPLN after CRT had a 55% higher recurrence rate, characterized by delayed local recurrence, a pattern that may be affected by certain chemokines. In conclusion, changes in initially positive LPLN (>7 mm) may predict the prognosis of patients with RC who receive preoperative CRT-TME. LPLN positivity after CRT was associated with shorter CSS and RFS. Strategies to improve patient survival may include selective LPLN dissection or more aggressive multimodality therapy.

Preoperative chemoradiotherapy for clinically diagnosed T3N0 rectal cancer

PURPOSE

This retrospective study compared the recurrence-free survival (RFS) and local recurrence rates of patients who received preoperative chemoradiotherapy (PCRT) for cT3N0 vs. those who did not.

METHODS

We analyzed the records of 593 patients with transrectal ultrasound (TUS) or magnetic resonance image (MRI)-staged cT3N0 mid and low locally advanced rectal cancer, including 255 who received PCRT and 338 who did not. The RFS and cumulative local recurrence rates were compared in the two groups. We also investigated the rates of pathologic complete response (pCR) and mesorectal lymph node (LN) involvement in the PCRT group.

RESULTS

The overall pCR rate was 13.3 %. Of the 338 non-PCRT patients, 125 (37.0 %) had pathologically positive mesorectal LNs. Sphincter-preserving surgery was performed in 431 (72.7 %) of the 593 patients, with similar rates in the two groups. However, the sphincter preservation rate in patients with low rectal cancer was higher among those who received PCRT than among those who did not (64.8 vs. 47 %, P = 0.002). The 5-year RFS (76.4 vs. 75.5 %, P = 0.92) and local recurrence (3.9 vs. 3.0 %, P = 0.97) rates were similar in the PCRT and non-PCRT groups.

CONCLUSION

Although PCRT did not improve the RFS or local recurrence rates, it increased the chance of sphincter preservation in patients with low rectal cancer. The advantages of PCRT for patients with cT3N0 should be re-evaluated considering the limitation of pretreatment staging, oncologic benefits, and improved sphincter preservation.

Factors associated with lateral pelvic recurrence after curative resection following neoadjuvant chemoradiotherapy in rectal cancer patients

PURPOSE

This study aims to determine the risk factors for lateral pelvic recurrence (LPR) in rectal cancer patients treated with neoadjuvant chemoradiotherapy (CRT) and curative surgery.

METHODS

Four hundred forty-three patients treated with neoadjuvant CRT and curative surgery from October 1999 through June 2009 were analyzed. All patients underwent total mesorectal resection without lateral pelvic lymph node (LPLN) dissection. Recurrence patterns and lateral pelvic recurrence-free survival (LPFS) were evaluated relative to clinicopathologic parameters including pelvic LN status.

RESULTS

Median follow-up was 52 months, with locoregional recurrence in 53 patients (11.9 %). Of the 53 patients, 28 (52.8 %) developed LPR, of which eight had both central and lateral PR. Multivariate analysis showed a significant relationship between LPFS and the number of lateral pelvic LN (p = 0.010) as well as the ratio of the number of positive LN/number of dissected LN (p = 0.038). The relationship between LPFS and LPLN size had a marginal trend (p = 0.085). Logistic regression analysis showed positive relationships between LPR probability and the number of LPLN (odds ratio [OR] 1.507; 95 % confidence interval [CI] 1.177-1.929; p = 0.001) as well as LPLN size (OR 1.124; CI 1.029-1.227, p = 0.009).

CONCLUSIONS

LPLN ≥ 2 and a ratio of the number of positive LN/number of dissected LN > 0.3 were prognostic of poor LPFS. The prediction curve of LPR according to the number and size of LPLN could be useful for determining the benefit of additional lateral pelvic treatment.

Robotic and laparoscopic pelvic lymph node dissection for rectal cancer: short-term outcomes of 21 consecutive series

PURPOSE

The aim of this study is to describe our initial experience and assess the feasibility and safety of robotic and laparoscopic lateral pelvic node dissection (LPND) in advanced rectal cancer.

METHODS

Between November 2007 and November 2012, extended minimally invasive surgery for LPND was performed in 21 selected patients with advanced rectal cancer, including 11 patients who underwent robotic LPND and 10 who underwent laparoscopic LPND. Extended lymphadenectomy was performed when LPN metastasis was suspected on preoperative magnetic resonance imaging even after chemoradiation.

RESULTS

All 21 procedures were technically successful without the need for conversion to open surgery. The median operation time was 396 minutes (range, 170-581 minutes) and estimated blood loss was 200 mL (range, 50-700 mL). The median length of stay was 10 days (range, 5-24 days) and time to removal of the urinary catheter was 3 days (range, 1-21 days). The median total number of lymph nodes harvested was 24 (range, 8-43), and total number of lateral pelvic lymph nodes was 7 (range, 2-23). Six patients (28.6%) developed postoperative complications; three with an anastomotic leakages, two with ileus and one patient with chyle leakage. Two patients (9.5%) developed urinary incontinence. There was no mortality within 30 days. During a median follow-up of 14 months, two patients developed lung metastasis and there was no local recurrence.

CONCLUSION

Robotic and laparoscopic LPND is technically feasible and safe. Minimally invasive techniques for LPND in selected patients can be an acceptable alternative to an open LPND.

EUS-FNA assessment of extramesenteric lymph node status in primary rectal cancer

BACKGROUND

Preoperative staging is an essential factor in the multidisciplinary management of rectal cancer. The accuracy of imaging alone with CT, magnetic resonance imaging, or rigid endorectal US is poor. The addition of EUS-FNA may enhance extramesenteric lymph node metastases detection (M1 disease) and overall staging accuracy.

OBJECTIVE

To evaluate the frequency of extramesenteric lymph node visualization by EUS and the rate of extramesenteric lymph node metastases by FNA. Secondary goals were to evaluate the clinical, endoscopic, and sonographic features associated with extramesenteric lymph node metastases, disease progression, and overall mortality.

DESIGN

Retrospective cohort study.

SETTINGS

Tertiary referral center.

RESULTS

Forty-one of 316 patients (13%) with primary rectal cancer over a 6-year period had M1 disease by EUS-FNA. Significant clinical, endoscopic, and sonographic features associated with extramesenteric lymph node metastases included the serum carcinoembryonic antigen level, tumor length 4 cm and longer, annularity 50% or more, sessile morphology, and lymph node size. The sensitivity and specificity of CT for extramesenteric lymph node metastases were 44% and 89%, respectively. Twenty-three of 316 rectal cancer endosonographic procedures (7.3%) were up-staged by FNA, which established extramesenteric lymph node metastases. Over a 4-year follow-up, disease progression and overall mortality of patients with extramesenteric lymph node metastases was observed in 6 patients (14.6%) and 14 patients (34%), respectively.

CONCLUSIONS

Preoperative EUS-FNA identification of extramesenteric lymph node metastases outside of standard radiation fields or total mesorectal excision resection margins could affect medical and surgical planning.