Factors influencing recurrence of stage I-III rectal cancer in regional Australia

Risk Factors for Recurrence After Surgery for Rectal Cancer in a Modern, Nationwide Population-Based Cohort

BACKGROUND

The success of modern multimodal treatment in rectal cancer is dependent on risk prediction. Better knowledge of the risk of locoregional and distant recurrence, in relation to preoperative treatment, pathological stage, and commonly used risk factors, is needed when deciding on adjuvant therapy and surveillance.

METHODS

The Swedish ColoRectal Cancer Registry was used to identify patients diagnosed with rectal adenocarcinoma between 2011 and 2018. Readily available variables, including patient, tumor, and treatment factors were exposures. Cox proportional hazard models were used to identify important risk factors for recurrence and calculate recurrence risks.

RESULTS

A total of 9428 curatively resected patients were included and followed for a median of 72 months. Eighteen percent had distal recurrence and 3% had locoregional recurrence at 5 years. Risk factors with major impact on distal recurrence were pT4a (hazard ratio [HR] 5.1, 95% confidence interval [CI] 3.3-8.0), pN2b (HR 3.4, 95% CI 2.7-4.2), tumor deposit (HR 1.7, 95% CI 1.5-1.9), lymph node yield (HR 1.5, 95% CI 1.3-1.8), and tumor level 0-5 cm (HR 1.5, 95% CI 1.3-1.8). Pathologic stage and number of risk factors identified groups with markedly different recurrence risks in all neoadjuvant treatment groups.

CONCLUSIONS

Readily available risk factors, as a complement to stage, are still valid and robust in all neoadjuvant treatment groups. Tumor deposit is important, while circumferential resection margin might no longer be important with improved oncological treatments and high-quality TME surgery. Tailored surveillance is possible in selected groups using risk stratification based on stage and risk factors.

Risk factors for recurrence in colorectal cancer: a retrospective analysis in a regional Australian hospital

BACKGROUND

Colorectal cancer is the third most commonly diagnosed malignancy in Australia. Up to a third of patients who have undergone surgery with curative intent for colorectal cancer will have a recurrence of disease leading to significant morbidity and mortality. Regional Australians have disproportionately worse outcomes.

AIM

To identify factors associated with recurrence in colorectal cancer patients treated at a regional Australian hospital.

METHODS

This study is a retrospective cohort analysis. Consecutive patients who have undergone curative resection at a regional public and private hospital by three surgeons from a single surgical practice for either rectal cancer or colon cancer were included. Prognostic indicators of recurrence were examined via both univariate and multivariate time-to-event analyses.

RESULTS

Three hundred nine patients were included with 43 recurrences. Thirty presented with distant metastases, seven presented with locoregional recurrence and six presented with locoregional as well as distant recurrence. In univariable analysis, higher rates of recurrence were associated with tumour type, higher AJCC summary stage, higher preoperative levels of CA19-9, perineural invasion, lymphovascular invasion, <12 nodes examined, positive lymph nodes and emergency surgery status. On multivariable analysis recurrence remained associated with tumours with a mucinous and/or signet cell component, positive nodes and <12 lymph nodes examined.

CONCLUSION

A combination of patient and treatment factors are relevant in determining the risk of recurrence for stage I-III colorectal cancer. This study emphasises the importance of histology in determining risk, particularly the number of nodes examined. CEA 19-9 may also be a useful pre-operative predictor of recurrence.

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.