Long-term oncologic outcome following preoperative combined modality therapy and total mesorectal excision of locally advanced rectal cancer

Chemoradiation for rectal cancer: rationale, approaches, and controversies

The standard adjuvant treatment of cT3 and/or N+ rectal cancer is preoperative chemoradiation. However, there are many controversies regarding this approach. These controversies include the role of short course radiation, whether postoperative adjuvant chemotherapy is necessary for all patients, and if the type of surgery following chemoradiation should be based on the response rate. More accurate imaging techniques and/or molecular markers may help identify patients with positive pelvic nodes to reduce the chance of overtreatment with preoperative therapy. Will more effective systemic agents both improve the results of radiation, as well as modify the need for pelvic radiation? These questions and others remain active areas of clinical investigation.

Pathologic complete response after neoadjuvant treatment for rectal cancer decreases distant recurrence and could eradicate local recurrence

BACKGROUND

The aim of this study was to evaluate the clinical implications of pathologic complete response (pCR) (i.e., T0N0M0) after neoadjuvant chemoradiation and radical surgery in patients with locally advanced rectal cancer.

MATERIALS AND METHODS

A single-center, prospectively maintained colorectal cancer database was queried for patients with primary cII and cIII rectal cancer staged by CT and ERUS/MRI undergoing long-course neoadjuvant chemoradiation followed by proctectomy with curative intent between 1997 and 2007. Patients were stratified into pCR and no-pCR groups and compared with respect to demographics, tumor and treatment characteristics, and oncologic outcomes. Outcomes evaluated were 5-year overall survival, disease-free survival, disease-specific mortality, local recurrence, and distant recurrence.

RESULTS

The query returned 238 patients (73% male), with a median age of 57 years and median follow-up of 54 months. Of these, 58 patients achieved pCR. Patients with pCR vs no-pCR were statistically comparable with respect to demographics, chemoradiation regimens, tumor distance from anal verge, clinical stage, surgical procedures performed, and follow-up time. No patient with pCR had local recurrence. Overall survival and distant recurrence were also significantly improved for patients achieving pCR.

CONCLUSIONS

Achievement of pCR after neoadjuvant chemoradiation is associated with greatly improved cancer outcomes in locally advanced rectal cancer. Future studies should evaluate the relationship between increases in pCR rates and improvements in cancer outcomes in this population.

Rectum-conserving surgery in the era of chemoradiotherapy

BACKGROUND

A complete pathological response occurs in 10-30 per cent of patients with locally advanced rectal cancer undergoing neoadjuvant chemoradiotherapy (CRT). The standard of care has been radical surgery with high morbidity risks and the challenges of stomata despite the favourable prognosis. This review assessed minimalist approaches (transanal excision or observation alone) to tumours with a response to CRT.

METHODS

A systematic review was performed using PubMed and Embase databases. Keywords included: 'rectal', 'cancer', 'transanal', 'conservative', 'complete pathological response', 'radiotherapy' and 'neoadjuvant'. Original articles from all relevant listings were sourced. These were hand searched for further articles of relevance. Main outcome measures assessed were rates of local recurrence and overall survival, and equivalence to radical surgery.

RESULTS

Purely conservative 'watch and wait' strategies after CRT are still controversial. Originally used for elderly patients or those who refused surgery, the data support transanal excision of rectal tumours showing a good response to CRT. A complete pathological response in the T stage (ypT0) indicates < 5 per cent risk of nodal metastases.

CONCLUSION

Rectal tumours showing an excellent response to CRT may be suitable for local excision, with equivalent outcomes to radical surgery. This approach should be the subject of prospective clinical trials in specialist centres.

Is local excision after complete pathological response to neoadjuvant chemoradiation for rectal cancer an acceptable treatment option?

PURPOSE

The role of local excision in patients with good histological response to neoadjuvant chemoradiation for locally advanced rectal cancer is unclear, mainly because of possible regional nodal involvement. This study aims to evaluate the correlation between pathological T and N stages following neoadjuvant chemoradiation for locally advanced rectal cancer and the outcome of patients with mural pathological complete response undergoing local excision.

METHODS

This investigation was conducted as a retrospective analysis. Between January 1997 and December 2007, 320 patients with T3 to 4Nx, TxN+ or distal (≤ 6 cm from the anus) T2N0 rectal cancer underwent neoadjuvant concurrent chemoradiation followed by surgery. Radiotherapy was standard and chemotherapy consisted of common fluoropyrimidine-based regimens.

RESULTS

After chemoradiation, 93% patients had radical surgery, 6% had local excision, and 3% did not have surgery. In the 291 patients undergoing radical surgery, the pathological T stage correlated with the N stage (P = .036). We compared the outcome of patients with mural complete pathological response (n = 37) who underwent radical surgery (group I) and those (n = 14) who had local excision only (group II). With a median follow-up of 48 months, 4 patients in group I had a recurrence and none in group II had a recurrence; one patient died in group I and none died in group II. Disease-free survival, pelvic recurrence-free survival, and overall survival rates were similar in both groups.

CONCLUSION

In this retrospective study, nodal metastases were rare in patients with mural complete pathological response following neoadjuvant chemoradiation (3%), and local excision did not compromise their outcome. Therefore, local excision may be an acceptable option in these patients.

Predictive factors of tumor response after neoadjuvant chemoradiation for locally advanced rectal cancer

PURPOSE

Neoadjuvant chemoradiation followed by surgery is the standard of care for locally advanced rectal cancer. The aim of this study was to correlate tumor response to survival and to identify predictive factors for tumor response after chemoradiation.

METHODS AND MATERIALS

From 1998 to 2008, 168 patients with histologically proven locally advanced adenocarcinoma treated by preoperative chemoradiation before total mesorectal excision were retrospectively studied. They received a radiation dose of 45 Gy with a concomitant 5-fluorouracil (5-FU)-based chemotherapy. Analysis of tumor response was based on lowering of the T stage between pretreatment endorectal ultrasound and pathologic specimens. Overall and progression-free survival rates were correlated with tumor response. Tumor response was analyzed with predictive factors.

RESULTS

The median follow-up was 34 months. Five-year disease-free survival and overall survival rates were, of 44.4% and 74.5% in the whole population, 83.4% and 83.4%, respectively, in patients with pathological complete response, 38.6% and 71.9%, respectively, in patients with tumor downstaging, and 29.1 and 58.9% respectively, in patients with absence of response. A pretreatment carcinoembryonic antigen (CEA) level of <5 ng/ml was significantly independently associated with pathologic complete tumor response (p = 0.019). Pretreatment small tumor size (p = 0.04), pretreatment CEA level of <5 ng/ml (p = 0.008), and chemotherapy with capecitabine (vs. 5-FU) (p = 0.04) were significantly associated with tumor downstaging.

CONCLUSIONS

Downstaging and complete response after CRT improved progression-free survival and overall survival of locally advanced rectal adenocarcinoma. In multivariate analysis, a pretreatment CEA level of <5 ng/ml was associated with complete tumor response. Thus, small tumor size, a pretreatment CEA level of < 5 ng/ml, and use of capecitabine were associated with tumor downstaging.

Long-term survival and recurrence outcomes following surgery for distal rectal cancer

BACKGROUND

Treatment of distal rectal cancer remains clinically challenging and includes proctectomy and coloanal anastomosis (CAA) or abdominoperineal resection (APR). The purpose of this study is to evaluate operative and pathologic factors associated with long-term survival and local recurrence outcomes in patients treated for distal rectal cancer.

METHODS

A retrospective consecutive cohort study of 304 patients treated for distal rectal cancer with radical resection from 1993 to 2003 was performed. Patients were grouped by procedure (CAA or APR). Demographic, pathologic, recurrence, and survival data were analyzed utilizing chi-square analysis for comparison of proportions. Survival analysis was performed using Kaplan-Meier method and log-rank test for univariate and Cox regression for multivariate comparison.

RESULTS

The median tumor distance from the anal verge was 2 cm [interquartile range (IQR) 0.5-4 cm]. Margins were negative in all but four patients (one distal, 0.3%; three radial, 1%). The 5-year overall survival rate was 82% (88.6% stage pI, 80.5% stage pII, 67.9% stage pIII). Older age, advanced pathologic stage, presence of lymphovascular or perineural invasion, earlier treatment period, and APR surgery type were associated with worse survival on multivariate analysis. The 5-year local recurrence rate was 5.3% after CAA and 7.9% after APR (p = 0.33).

CONCLUSIONS

Low rates of local recurrence and good overall survival can be achieved after treatment of distal rectal cancer with stage-appropriate chemoradiation and proctectomy with CAA or APR. Sphincter preservation can be achieved even with distal margins less than 2 cm.

A Phase II trial of neoadjuvant preoperative chemoradiotherapy with S-1 plus irinotecan and radiation in patients with locally advanced rectal cancer: clinical feasibility and response rate

PURPOSE

We aimed to validate our hypothesis that a preoperative chemoradiotherapy regimen with S-1 plus irinotecan is feasible, safe, and active for the management of locally advanced rectal cancer in a single-arm Phase II setting.

METHODS AND MATERIALS

Eligible patients had previously untreated, locally advanced rectal adenocarcinoma. Radiotherapy was administered in fractions of 1.8 Gy/d for 25 days. S-1 was administered orally in a fixed daily dose of 80 mg/m2 on Days 1 to 5, 8 to 12, 22 to 26, and 29 to 33. Irinotecan (80 mg/m2) was infused on Days 1, 8, 22, and 29. Four or more weeks after the completion of the treatment, total mesorectal excision with lateral lymph node dissection was performed. The primary endpoint was the rate of completing treatment in terms of feasibility. The secondary endpoints were the response rate and safety.

RESULTS

We enrolled 43 men and 24 women in the study. The number of patients who completed treatment was 58 (86.6%). Overall, 46 patients (68.7%) responded to treatment and 24 (34.7%) had a complete histopathologic response. Three patients had Grade 3 leukopenia, and another three patients had Grade 3 neutropenia. Diarrhea was the most common type of nonhematologic toxicity: 3 patients had Grade 3 diarrhea.

CONCLUSIONS

A preoperative regimen of S-1, irinotecan, and radiotherapy to the rectum was feasible, and it appeared safe and effective in this nonrandomized Phase II setting. It exhibited a low incidence of adverse events, a high rate of completion of treatment, and an extremely high rate of pathologic complete response.

Clinical significance of CD133 and hypoxia inducible factor-1α gene expression in rectal cancer after preoperative chemoradiotherapy

AIMS

The mechanism of distant recurrence in rectal cancer after preoperative chemoradiotherapy (CRT) has yet to be fully elucidated. Further improvements in survival rates cannot be achieved without decreasing distant recurrence after preoperative CRT. Recently, it was reported that hypoxic conditions were correlated with cancer stem cell generation. Therefore, we investigated the correlation between the expression of CD133 and hypoxia inducible factor-1α (HIF-1α), and their association with clinical outcome.

MATERIALS AND METHODS

Fifty-two patients with rectal cancer underwent preoperative CRT. Residual cancer cells after CRT were obtained from formalin-fixed paraffin-embedded specimens using micro-dissection. The expression levels of CD133 (PROM1) and HIF-1α genes were measured using real-time reverse transcription polymerase chain reaction. The correlation between expression and irradiation was evaluated using colon cancer cell lines. Immunohistochemical staining of these proteins after CRT was also investigated.

RESULTS

We observed a significant inverse correlation between the gene expression of CD133 (PROM1) and HIF-1α genes in residual cancer cells after CRT. Elevated CD133 gene expression was associated with distant recurrence and poor recurrence-free survival. Elevated HIF-1α gene expression was associated with poor overall survival. In vitro, the change in gene expression levels after irradiation showed inverse patterns. Immunohistochemical analyses showed that residual cancer cells strongly expressed CD133 and lacked HIF-1α expression.

CONCLUSION

Our results suggest that CD133 and HIF-1α expression is associated with tumour re-growth and distant recurrence after CRT. These results may assist in clarifying the development of future cancer therapeutics in rectal cancer patients undergoing preoperative CRT.

Long-term outcome in patients with a pathological complete response after chemoradiation for rectal cancer: a pooled analysis of individual patient data

BACKGROUND

Locally advanced rectal cancer is usually treated with preoperative chemoradiation. After chemoradiation and surgery, 15-27% of the patients have no residual viable tumour at pathological examination, a pathological complete response (pCR). This study established whether patients with pCR have better long-term outcome than do those without pCR.

METHODS

In PubMed, Medline, and Embase we identified 27 articles, based on 17 different datasets, for long-term outcome of patients with and without pCR. 14 investigators agreed to provide individual patient data. All patients underwent chemoradiation and total mesorectal excision. Primary outcome was 5-year disease-free survival. Kaplan-Meier survival functions were computed and hazard ratios (HRs) calculated, with the Cox proportional hazards model. Subgroup analyses were done to test for effect modification by other predicting factors. Interstudy heterogeneity was assessed for disease-free survival and overall survival with forest plots and the Q test.

FINDINGS

484 of 3105 included patients had a pCR. Median follow-up for all patients was 48 months (range 0-277). 5-year crude disease-free survival was 83.3% (95% CI 78.8-87.0) for patients with pCR (61/419 patients had disease recurrence) and 65.6% (63.6-68.0) for those without pCR (747/2263; HR 0.44, 95% CI 0.34-0.57; p<0.0001). The Q test and forest plots did not suggest significant interstudy variation. The adjusted HR for pCR for failure was 0.54 (95% CI 0.40-0.73), indicating that patients with pCR had a significantly increased probability of disease-free survival. The adjusted HR for disease-free survival for administration of adjuvant chemotherapy was 0.91 (95% CI 0.73-1.12). The effect of pCR on disease-free survival was not modified by other prognostic factors.

INTERPRETATION

Patients with pCR after chemoradiation have better long-term outcome than do those without pCR. pCR might be indicative of a prognostically favourable biological tumour profile with less propensity for local or distant recurrence and improved survival.

FUNDING

None.

Patterns of response after preoperative treatment in gastric cancer

PURPOSE

To analyze the rate of pathologic response in patients with locally advanced gastric cancer treated with preoperative chemotherapy with and without chemoradiation at our institution.

METHODS AND MATERIALS

From 2000 to 2007 patients were retrospectively identified who received preoperative treatment for gastric cancer (cT3-4/ N+) with induction chemotherapy (Ch) or with Ch followed by concurrent chemoradiotherapy (45 Gy in 5 weeks) (ChRT). Surgery was planned 4-6 weeks after the completion of neoadjuvant treatment. Pathologic assessment was used to investigate the patterns of pathologic response after neoadjuvant treatment.

RESULTS

Sixty-one patients were analyzed. Of 61 patients, 58 (95%) underwent surgery. The R0 resection rate was 87%. Pathologic complete response was achieved in 12% of the patients. A major pathologic response (<10% of residual tumor) was observed in 53% of patients, and T downstaging was observed in 75%. Median follow-up was 38.7 months. Median disease-free survival (DFS) was 36.5 months. The only patient-, tumor-, and treatment-related factor associated with pathologic response was the use of preoperative ChRT. Patients achieving major pathologic response had a 3-year actuarial DFS rate of 63%.

CONCLUSIONS

The patterns of pathologic response after preoperative ChRT suggest encouraging intervals of DFS. Such a strategy may be of interest to be explored in gastric cancer.

Correlation of CD133, OCT4, and SOX2 in rectal cancer and their association with distant recurrence after chemoradiotherapy

BACKGROUND

Cancer stem cells are associated with metastatic potential, treatment resistance, and poor patient prognosis. Distant recurrence remains the major cause of mortality in rectal cancer patients with preoperative chemoradiotherapy (CRT). We investigated the role of three stem cell markers (CD133, OCT4, and SOX2) in rectal cancer and evaluated the association between these gene levels and clinical outcome in rectal cancer patients with preoperative CRT.

METHODS

Thirty-three patients with rectal cancer underwent preoperative CRT. Total RNAs of rectal cancer cells before and after CRT were isolated. Residual cancer cells after CRT were obtained from formalin-fixed paraffin-embedded (FFPE) specimens using microdissection. The expression levels of three stem cell genes were measured using real-time reverse-transcription polymerase chain reaction (RT-PCR). The association between these gene levels and radiation was evaluated using colon cancer cell lines. Immunohistochemical staining of these markers after CRT was also investigated.

RESULTS

There were significant positive correlations among the three genes after CRT. Patients who developed distant recurrence had higher levels of the three genes compared with those without recurrence in residual cancer after CRT. These elevated gene levels were significantly associated with poor disease-free survival. The radiation caused upregulation of these gene levels in LoVo and SW480 in vitro. Immunohistochemically, CD133 staining was observed in not only luminal surface but also cytoplasm.

CONCLUSIONS

Expression of CD133, OCT4, and SOX2 may predict distant recurrence and poor prognosis of rectal cancer patients treated with preoperative CRT. Correlations among these genes may be associated with tumor regrowth and metastatic relapse after CRT.

Impact of tumor response on survival after radiochemotherapy in locally advanced rectal carcinoma

In locally advanced rectal adenocarcinoma, preoperative radiochemotherapy induces tumor response. The impact of pathologic tumor response on survival is still debated because of the numerous distinct tumor-response gradings available in the literature and the lack of standardized pathologic approach. The objective of this work was to study the impact of tumor response on survival, according to the 4 main tumor-response gradings available in the literature in locally advanced rectal adenocarcinoma after preoperative radiochemotherapy. From 1995 to 2004, 292 consecutive patients with cT3-T4 and/or N+ rectal adenocarcinoma were enrolled. Tumor response was evaluated according to ypTN-response gradings (downstaging: ypT0-2 N0 and complete pathologic response: ypT0 N0) and cellular-response gradings (ie, Mandard et al's and Rodel et al's gradings). The impact of tumor-response gradings and of different clinicopathologic variables on 5-year disease-free and overall survival were studied by univariate and multivariate analyses. We found that all tumor-response gradings were associated with survival. However, multivariate analysis showed that downstaging was the only tumor-response grading that influenced survival independently. In the subgroup of stage II patients (n=99), we also observed no difference on both 5-year disease-free and overall survival between low and high responders according to cellular response. In conclusion, in our experience, downstaging is the only tumor-response grading that influenced survival independently in locally advanced rectal adenocarcinomas. Cellular-response gradings had no impact on survival even in stage II patients.

Colorectal cancer

Substantial progress has been made in colorectal cancer in the past decade. Screening, used to identify individuals at an early stage, has improved outcome. There is greater understanding of the genetic basis of inherited colorectal cancer and identification of patients at risk. Optimisation of surgery for patients with localised disease has had a major effect on survival at 5 years and 10 years. For rectal cancer, identification of patients at greatest risk of local failure is important in the selection of patients for preoperative chemoradiation, a strategy proven to improve outcomes in these patients. Stringent postoperative follow-up helps the early identification of potentially radically treatable oligometastatic disease and improves long-term survival. Treatment with adjuvant fluoropyrimidine for colon and rectal cancers further improves survival, more so in stage III than in stage II disease, and oxaliplatin-based combination chemotherapy is now routinely used for stage III disease, although efficacy must be carefully balanced against toxicity. In stage II disease, molecular markers such as microsatellite instability might help select patients for treatment. The integration of targeted treatments with conventional cytotoxic drugs has expanded the treatment of metastatic disease resulting in incremental survival gains. However, biomarker development is essential to aid selection of patients likely to respond to therapy, thereby rationalising treatments and improving outcomes.

Imaging as a surveillance tool in rectal cancer

Despite advances in diagnosis and treatment, half of patients with treated rectal cancer will die owing to recurrent disease. There is no evidence of benefit on survival from an intensive surveillance program, even if presymptomatic recurrent disease is detected. The aim of this article is to review the results described for the different imaging techniques in diagnosing rectal cancer recurrence in different sites and to discuss their relative clinical impact. The sensitivity of imaging techniques is related to the performance of the machines and the site being examined. Computed tomography is the most used technique owing to its availability, speed, panoramic images and ease of use, while MRI of the pelvis and the liver produces the highest resolution, sensitivity and specificity in these anatomical areas. Owing to its high cost, [(18)F] fluorodeoxyglucose-PET should be used as a third-level examination, a 'problem-solving' method when the site of recurrence is unknown or to rule out other possible sites of recurrence before a second surgery, and, finally, because it offers the possibility to investigate the whole body. The follow-up must be designed for individual patients, taking into account a number of factors. In the near future, whole-body imaging, probably by MRI, that is free from radiation will become the method of choice for screening for recurrent disease.

PET/CT pattern analysis for surgical staple line recurrence in patients with colorectal cancer

OBJECTIVE

The purpose of our study was to determine whether (18)F-FDG PET/CT interpretation with metabolic-anatomic pattern analysis can be used to accurately assess for surgical staple line recurrence after colorectal cancer resection.

MATERIALS AND METHODS

Seventy-nine consecutive patients with previous surgical resection of colorectal cancer were studied retrospectively. The surgical anastomotic or Hartmann's pouch staple lines were evaluated for presence or absence of tumor recurrence with FDG PET/CT metabolic-anatomic pattern analysis. Focal, eccentric, or perianastomotic CT masses with any associated PET pattern were regarded as positive for staple line recurrence. If the perianastomotic CT abnormality was presacral in location, then FDG uptake at least as intense as normal liver was required for positive interpretation. Eccentric or perianastomotic PET patterns matched with normal or diffuse thickening CT patterns were regarded as indeterminate. Presence or absence of recurrent tumor was confirmed by pathology, surgery, colonoscopy, imaging follow-up of at least 3 months, or clinical follow-up of at least 1 year.

RESULTS

Nine patients (11.4%) had staple line recurrence and 70 (88.6%) did not. FDG PET/CT interpretation yielded sensitivity, specificity, positive predictive value, negative predictive value, and accuracy results of 100% (9/9), 97.1% (68/70), 81.8% (9/11), 100% (68/68), and 97.5% (77/79), respectively. All nine patients with staple line recurrence showed perianastomotic or eccentric masses on CT, eight with matching perianastomotic or eccentric FDG uptake patterns. Background, diffuse, curvilinear, or focal FDG uptake patterns, regardless of FDG uptake intensity, paired with normal findings or diffuse mural thickening on CT were seen only in patients without staple line recurrence.

CONCLUSION

FDG PET/CT pattern analysis enables accurate assessment for staple line recurrence in patients with previous resection of colorectal cancer. The most reliable PET/CT pattern predicting staple line recurrence is an eccentric or perianastomotic mass on CT with corresponding eccentric or perianastomotic FDG uptake on PET. Background, diffuse (on one or both sides of the staple line), curvilinear, and focal patterns of FDG uptake do not correlate with recurrence in the absence of a mass on CT.

Stromal CXCR4 and CXCL12 expression is associated with distant recurrence and poor prognosis in rectal cancer after chemoradiotherapy

BACKGROUND

Distant recurrence remains the major cause of mortality in rectal cancer patients with preoperative chemoradiotherapy (CRT). Recently, cancer stroma has been implicated in influencing proliferation, invasion, and metastasis of cancer cells. It has been reported that expression of CXCR4 and its ligand CXCL12 are associated with migration, invasion, and proliferation of colorectal cancer.

MATERIALS AND METHODS

A total of 53 patients with rectal cancer underwent preoperative CRT. Total RNAs of residual rectal cancer stromal cells after CRT were obtained from formalin-fixed paraffin-embedded (FFPE) specimens using microdissection. The expression levels of CXCR4 and CXCL12 genes were measured using real-time reverse transcription polymerase chain reaction (RT-PCR). Immunohistochemical staining of these markers after CRT was also investigated.

RESULTS

Of the 53 patients, 16 (30.1%) and 14 (26.4%) showed detectable CXCR4 and CXCL12 levels, respectively. We found a significant positive correlation between expression levels of CXCR4 and CXCL12. Patients who developed distant recurrence had twofold higher expression levels of both CXCR4 and CXCL12 compared with those without recurrence after CRT (P < 0.01). Elevated expression levels were also associated with poor probability of recurrence-free survival in both genes (P < 0.01). Additionally, positive CXCL12 expression, but not CXCR4, was significantly correlated with poorer overall survival (P < 0.01). CXCR4 and CXCL12 expression determined using immunohistochemistry was observed in not only cancer but also stromal cells.

CONCLUSION

Our results suggest that evaluation of the expression of both genes may be useful for predicting distant recurrence and poor prognosis in rectal cancer patients treated with preoperative CRT followed by surgery.

Downstaging without complete pathologic response after neoadjuvant treatment improves cancer outcomes for cIII but not cII rectal cancers

BACKGROUND

The aim of this study was to evaluate whether downstaging impacts prognosis in patients with cII versus cIII rectal cancer.

MATERIALS AND METHODS

We identified from our colorectal cancer database 295 patients with primary cII and cIII rectal cancer staged by CT and ERUS/MRI who received 5-FU-based chemoradiation followed by R0 surgery after a median interval of 7 weeks during 1997-2007. The median radiotherapy dose was 5040 cGy. We excluded 58 patients with pathologic complete response (pCR) and compared among the remaining 162 patients pathologic downstaging (cII to ypI, cIII to ypII or ypI) versus no pathologic downstaging (c stage < or = yp stage). Outcomes evaluated were 5-year overall survival, 3-year cancer-specific survival, disease-free survival, overall recurrence, local recurrence, and distant recurrence.

RESULTS

The median age was 58 years and median follow-up was 48 months. Patients with downstaging versus no downstaging were statistically comparable with respect to demographics, chemoradiation regimen, interval time between neoadjuvant chemoradiation and surgery, tumor distance from anal verge, surgical procedures performed, and follow-up time. With the exception of local recurrence rates, downstaging resulted in significantly improved cancer outcomes for cIII but not cII.

CONCLUSIONS

Downstaging without pCR is a significant prognostic factor for patients with stage cIII rectal cancer. Tumor response to neoadjuvant chemoradiation should be taken into account when defining the optimal adjuvant chemotherapy regimen for patients with cIII rectal cancer.

GLUT-1 expression and response to chemoradiotherapy in rectal cancer

Preoperative chemoradiotherapy is used in locally advanced rectal cancer to reduce local recurrence and improve operability, however a proportion of tumors do not undergo significant regression. Identification of predictive markers of response to chemoradiotherapy would improve patient selection and may allow response modification by targeting of specific pathways. The aim of this study was to determine whether expression of glucose transporter-1 (GLUT-1) and p53 in pretreatment rectal cancer biopsies was predictive of tumor response to chemoradiotherapy. Immunohistochemical staining for GLUT-1 and p53 was performed on 69 pretreatment biopsies and compared to tumor response in the resected specimen as determined by the tumor regression grade (TRG) scoring system. GLUT-1 expression was significantly associated with reduced response to chemoradiotherapy and increasing GLUT expression correlated with poorer response (p=0.02). GLUT-1 negative tumors had a 70% probability of good response (TRG3/4) compared to a 31% probability of good response in GLUT-1 positive tumors. GLUT-1 may be a useful predictive marker of response to chemoradiotherapy in rectal cancer.

Factors associated with local recurrence after neoadjuvant chemoradiation with total mesorectal excision for rectal cancer

BACKGROUND

The purpose of the present study was to investigate risk factors associated with local recurrence in patients with locally advanced rectal cancer who received preoperative chemoradiotherapy in combination with total mesorectal excision (TME).

METHODS

Rectal cancer patients who were treated with neoadjuvant chemoradiation with TME were studied. We compared 26 patients who developed local recurrence with 119 recurrence-free patients during the follow-up period.

RESULTS

The median follow-up period was 52 months (range: 14-131 months). Based on the use of univariate and multivariate analyses, circumferential margin involvement (p = 0.02), the presence of lymphovascular or perineural invasion (p = 0.02), and positive nodal disease (p = 0.03) were contributing factors for local recurrence. The local recurrence rate was different between ypN(+) patients and ypN(-) patients with more than 12 nodes retrieved (p = 0.01). There was no difference in local recurrence rates between ypN(+) patients and ypN(-) patients with < 12 nodes (p = 0.35) or between ypN(-) patients with < 12 nodes or > or = 12 nodes (p = 0.18).

CONCLUSIONS

Patients with circumferential margin involvement, the presence of lymphovascular or perineural invasion, and positive nodal disease should be regarded as a high-risk group. We also determined that lymph node retrieval (< 12 nodes) in patients with node-negative disease was a risk factor for local recurrence.

Increased spontaneous apoptosis, but not survivin expression, is associated with histomorphologic response to neoadjuvant chemoradiation in rectal cancer

PURPOSE

Survivin has been shown to be an important mediator of cellular radioresistance in vitro. This study aims to compare survivin expression and apoptosis to histomorphologic responses to neoadjuvant radiochemotherapy (RCT) in rectal cancer.

MATERIALS AND METHODS

Thirty-six pre-treatment biopsies were studied. Survivin mRNA and protein expression plus TUNEL staining for apoptosis was performed. Response to treatment was assessed using a 5-point tumour regression grade.

RESULTS

Survivin expression was not found to be predictive of response to RCT (p = NS). In contrast, spontaneous apoptosis was significantly (p = 0.0051) associated with subsequent response to RCT. However, no association between survivin expression and levels of apoptosis could be identified.

CONCLUSIONS

This in vivo study failed to support in vitro studies showing an association between survivin and response to chemotherapy and radiation therapy. These results caution against the translation of the in vitro properties of survivin into a clinical setting.

Postoperative chemotherapy after neoadjuvant chemoradiation and surgery for rectal cancer: is it essential for patients with ypT0-2N0?

BACKGROUND

The potential advantage of adjuvant chemotherapy in patients with ypT0-2N0 rectal cancer remains unclear. The purpose of this study was to evaluate whether this therapy has an impact on survival.

MATERIALS AND METHODS

Patients who underwent curative surgery after preoperative chemoradiation for locally advanced low rectal cancer were retrospectively reviewed. A total of 41 consecutive patients with pathological stage 0 (ypT0N0) or I (ypT1-2N0) were enrolled. Of the 41 patients, 17 (41.5%) received postoperative 5-fluorouracil (5-FU)-based chemotherapy, while 24 were followed without postoperative therapy. Oncologic outcomes were compared between the two groups.

RESULTS

The median follow-up period was 47.6 months. The overall postoperative complication rates did not differ significantly between the patients who received chemotherapy and those who did not (17.6% vs. 20.8%, P = 0.799). The 5-year overall and disease-free survival rates for patients who received chemotherapy were 88.9% and 84.7%, which were not significantly different from the rates for those who did not (85.9%; P = 0.644 and 73.4%; P = 0.599, respectively).

CONCLUSIONS

Postoperative adjuvant chemotherapy for patients with good responses after preoperative chemoradiation and curative surgery did not significantly improve the survival. However, this should be validated in prospective randomized trials with larger sample sizes.

Pathologic nodal classification is the most discriminating prognostic factor for disease-free survival in rectal cancer patients treated with preoperative chemoradiotherapy and curative resection

PURPOSE

We retrospectively evaluated the effects of clinical and pathologic factors on disease-free survival (DFS) with the aim of identifying the most discriminating factor predicting DFS in rectal cancer patients treated with preoperative chemoradiotherapy (CRT) and curative resection.

METHODS AND MATERIALS

The study involved 420 patients who underwent preoperative CRT and curative resection between August 2001 and October 2006. Gender, age, distance from the anal verge, histologic type, histologic grade, pretreatment carcinoembryonic antigen (CEA) level, cT, cN, cStage, circumferential resection margin, type of surgery, preoperative chemotherapy, adjuvant chemotherapy, ypT, ypN, ypStage, and tumor regression grade (TRG) were analyzed to identify prognostic factors associated with DFS. To compare the discriminatory prognostic ability of four tumor response-related pathologic factors (ypT, ypN, ypStage, and TRG), the Akaike information criteria were calculated.

RESULTS

The 5-year DFS rate was 75.4%. On univariate analysis, distance from the anal verge, histologic type, histologic grade, pretreatment CEA level, cT, circumferential resection margin, type of surgery, preoperative chemotherapeutic regimen, ypT, ypN, ypStage, and TRG were significantly associated with DFS. Multivariate analysis showed that the four parameters ypT, ypN, ypStage, and TRG were, consistently, significant prognostic factors for DFS. The ypN showed the lowest Akaike information criteria value for DFS, followed by ypStage, ypT, and TRG, in that order.

CONCLUSION

In our study, ypT, ypN, ypStage, and TRG were important prognostic factors for DFS, and ypN was the most discriminating factor.

Lymphovascular invasion in rectal cancer following neoadjuvant radiotherapy: A retrospective cohort study

AIM: To investigate the meaning of lymphovascular invasion (LVI) in rectal cancer after neoadjuvant radiotherapy.

METHODS: A total of 325 patients who underwent radical resection using total mesorectal excision (TME) from January 2000 to January 2005 in Beijing cancer hospital were included retrospectively, divided into a preoperative radiotherapy (PRT) group and a control group, according to whether or not they underwent preoperative radiation. Histological assessments of tumor specimens were made and the correlation of LVI and prognosis were evaluated by univariate and multivariate analysis.

RESULTS: The occurrence of LVI in the PRT and control groups was 21.4% and 26.1% respectively. In the control group, LVI was significantly associated with histological differentiation and pathologic TNM stage, whereas these associations were not observed in the PRT group. LVI was closely correlated to disease progression and 5-year overall survival (OS) in both groups. Among the patients with disease progression, LVI positive patients in the PRT group had a significantly longer median disease-free period (22.5 mo vs 11.5 mo, P = 0.023) and overall survival time (42.5 mo vs 26.5 mo, P = 0.035) compared to those in the control group, despite the fact that no significant difference in 5-year OS rate was observed (54.4% vs 48.3%, P = 0.137). Multivariate analysis showed the distance of tumor from the anal verge, pretreatment serum carcinoembryonic antigen level, pathologic TNM stage and LVI were the major factors affecting OS.

CONCLUSION: Neoadjuvant radiotherapy does not reduce LVI significantly; however, the prognostic meaning of LVI has changed. Patients with LVI may benefit from neoadjuvant radiotherapy.

Rectal cancer

Surgery is the cornerstone of rectal cancer treatment. Oncological cure and overall survival continue to be the main goals, but sparing of the anal sphincter mechanism and functional results are also important. The modern management of rectal cancer is a multidisciplinary approach, and pre-operative staging is of crucial importance when planning treatment in these patients. Pre-operative staging is used to determine the indication for neoadjuvant therapy prior to surgical resection or to determine whether local excision is an option in carefully selected patients with early rectal cancer. Surgery in the form of total mesorectal excision (TME) has become the standard of care for mid and distal rectal cancers. Early rectal cancers do not require neoadjuvant therapy. For locally advanced cancers of the lower two-thirds of the rectum, the combination of surgical resection with chemoradiotherapy decreases local recurrence rates and probably improves overall survival. Whereas in the past local excision was only contemplated in patients who were unfit for radical surgery or for local palliation in cases of metastatic disease, over the last number of years there has been increasing interest in local treatment with curative intent in early rectal cancer.

The prognostic impact of the number of lymph nodes retrieved after neoadjuvant chemoradiotherapy with mesorectal excision for rectal cancer

BACKGROUND

We aimed to assess factors associated with the number of nodes retrieved and the impact of the number of lymph nodes in rectal cancer patients who underwent neoadjuvant chemoradiation with radical surgery.

METHODS

A total of 258 patients were enrolled. Lymph nodes were retrieved from specimens using a manual dissection technique.

RESULTS

Of the 258 patients, nine patients had an absence of lymph nodes (ypNx), 150 patients had a node-negative status (ypN(-)) and 99 patients had node-positive disease (ypN(+)). An advanced ypT classification (ypT3,4) and larger tumor (>4 cm) were associated with an increased number of nodes retrieved. The pretreatment CEA level (>5 ng/ml) and ypN(+) classification were significant risk factors for cancer specific and recurrence free survival. There was no significant difference of oncological outcomes among ypNx patients and a subset of ypN(-) patients based on the number of nodes retrieved using three cutoff values (1-11, 12-25, and 25-65 nodes).

CONCLUSIONS

In a neoadjuvant setting, ypN(+) disease was an independent risk factor for oncological outcomes. An absence of nodes does not represent an inferior oncological outcome. The number of nodes does not seen to impact survival and recurrence in ypN(-) patients.

High Ki67, Bax, and thymidylate synthase expression well correlates with response to chemoradiation therapy in locally advanced rectal cancers: proposal of a logistic model for prediction

Background:

Recently, preoperative chemoradiation therapy (CRT) for rectal cancer has been increasingly used as a neoadjuvant treatment. In the present study, the relation between histological response to CRT and immunohistochemical markers in biopsy specimens was investigated.

Methods:

Biopsy specimens from a total of 60 patients were collected before preoperative CRT with S-1 and irinotecan, and liniac 45 Gy. Immunohistochemical staining for Ki67, Mcm3, Bax, Bcl-2, ssDNA, Grp78, thymidylate synthase (TS), dihydropyrimidine dehydrogenase (DPD), CD34, vascular endothelial growth factor, nestin, and L-type amino-acid transporter 1 was performed to allow comparison of the Ki67 labelling index (LI), Bax score, TS score, DPD score, microvessel density by CD34, and Grp78 score with cancer regression.

Results:

When the cases were divided into responders (Dworak grades 3 and 4) and non-responders (grades 1 and 2) groups, good correlations were evident with Ki67 LI, Bax, Grp78, and TS expression. On multiple logistic regression analysis, Ki67 LI, Bax, and TS scores were found to be independent factors. With their use in a logistic model, P-values could predict responder cases with a sensitivity of 82.8% and a specificity of 83.9%.

Conclusion

Using this system, treatment strategy for locally advanced rectal cancers can be determined before chemoradiation.

Treatment for patients with rectal cancer and a clinical complete response to neoadjuvant therapy: a decision analysis

PURPOSE

A clinical complete response to neoadjuvant therapy occurs in a subset of patients with rectal cancer. Management of these patients is controversial and tension exists between the recurrence risk with observation, and the impact of surgery on quality-of-life. Therefore, the objective was to develop a decision-analytic model to evaluate the relative benefits of surgery vs. observation in rectal cancer patients who achieve clinical complete response after neoadjuvant chemoradiation.

METHODS

Clinically relevant inputs and events, including the ability to identify complete responders, likelihood of relapse and of salvage surgery after relapse, and utilities for each health state, were simulated by use of a Markov state-transition model. Transition probabilities and health-state utilities were derived from the literature and expert consensus. One-way and two-way sensitivity analyses were performed to assess the robustness of model results to assumptions. The primary outcome was quality-adjusted life expectancy.

RESULTS

In the base-case analysis, the quality-adjusted life expectancy with surgery exceeded observation (5.63 vs. 5.34 quality-adjusted life-years). Sensitivity analysis demonstrated that observation was preferred to surgery if the ability to correctly identify patients with true complete responses exceeded 58 percent, if quality-of-life after surgery was poor (utility <0.81), or if the relative reduction in recurrence risk with surgery was <43 percent when compared with observation.

CONCLUSIONS

Our model outlines the issues associated with surgery vs. observation, and suggests that surgery is beneficial for the average patient with rectal cancer with a clinical complete response after neoadjuvant therapy. Current limitations in the clinical assessment of patient response to chemoradiation constitute an important factor influencing our results, and therefore warrant further investigation.

Radiopharmaceuticals in preclinical and clinical development for monitoring of therapy with PET

This review article discusses PET agents, other than (18)F-FDG, with the potential to monitor the response to therapy before, during, or after therapeutic intervention. This review deals primarily with non-(18)F-FDG PET tracers that are in the final stages of preclinical development or in the early stages of clinical application for monitoring the therapeutic response. Four sections related to the nature of the tracers are included: radiotracers of DNA synthesis, such as the 2 most promising agents, the thymidine analogs 3'-(18)F-fluoro-3'-deoxythymidine and (18)F-1-(2'-deoxy-2'-fluoro-beta-d-arabinofuranosyl)thymine; agents for PET imaging of hypoxia within tumors, such as (60/62/64)Cu-labeled diacetyl-bis(N(4)-methylthiosemicarbazone) and (18)F-fluoromisonidazole; amino acids for PET imaging, including the most popular such agent, l-[methyl-(11)C]methionine; and agents for the imaging of tumor expression of androgen and estrogen receptors, such as 16beta-(18)F-fluoro-5alpha-dihydrotestosterone and 16alpha-(18)F-fluoro-17beta-estradiol, respectively.

Magnetic resonance imaging accuracy in assessing tumour down-staging following chemoradiation in rectal cancer

OBJECTIVE

Magnetic resonance imaging (MRI) is increasingly accepted as the radiological modality of choice staging rectal cancer but is subject to error. Neoadjuvant therapy is increasingly used in rectal cancer and MRI is used to stage response and occasionally plan surgery. We aim to assess the staging accuracy of MRI following chemoradiotherapy in rectal cancer.

METHOD

Retrospective analysis of 86 patients with MRI stage pre- and postlong-course chemoradiotherapy and comparison with pathological assessment.

RESULTS

Fourty-nine patients (34 men, 15 women) with median age 68 years (60-74) were analysed. The median time from completion of CRT to MRI was 32 days (16-37). Chemoradiotherapy led to significant down-staging (P < 0.001). MRI-staging accuracy was 43% (21/49) with over- and under-staging in 43% (21/49) and 14% (7/49) respectively. T-stage accuracy was 45% (22/49) with over-staging in 33% (16/49) and under-staging in 22% (11/49). MRI stage correlated poorly with pathological assessment for International Union Against Cancer (kappa = 0.255) and T stages (kappa = 0.112). MRI nodal assessment was 71% (35/49) accurate, with 82% (9/11) sensitivity, 68% (26/38) specificity and positive predictive value (PPV) of 43% (9/21) and negative predictive value of 93% (26/28). There was a significant difference in node positivity between MRI and pathological staging (P = 0.005, Fisher's exact). Complete radiological response was observed in 4% (2/49). Complete pathological response was observed in 10% (5/49), which were staged 0(1), I(1), II(2) and III(1) postchemoradiotherapy by MRI.

CONCLUSION

MRI staging following chemoradiation is poor. Over-staging occurs three times more commonly than under-staging. Over-staging is due to poor PPV of nodal assessment.

Oncologic outcomes after radical surgery following preoperative chemoradiotherapy for locally advanced lower rectal cancer: abdominoperineal resection versus sphincter-preserving procedure

BACKGROUND

Over the past several years, preoperative chemoradiotherapy (CRT) has contributed remarkably to make more sphincter-preserving procedure (SPP) possible for lower rectal cancer. The aim of this study was to compare the outcomes between abdominoperineal resection (APR) and SPP after preoperative CRT in patients with locally advanced lower rectal cancer.

METHODS

A retrospective investigation was conducted with a total of 122 patients who underwent radical surgery combined with preoperative CRT for locally advanced lower rectal cancer. Of these, 50 patients underwent APR and 72 received SPP. Surgery was performed 6-8 weeks after completion of preoperative CRT. Oncologic outcomes were compared between the two groups, and the clinicopathologic factors affecting the treatment outcomes were evaluated.

RESULTS

Circumferential resection margin (CRM) involvement (P = 0.037) and postoperative complication rate (P = 0.032) were significantly different between APR and SPP. Patients who underwent APR had a higher 5-year local recurrence (22.0% vs. 11.5%, P = 0.028) and lower 5-year cancer-specific survival (52.9% vs. 71.1%, P = 0.03) rate than those who underwent SPP. Pathologic N stage was the most critical predictor for local recurrence and survival.

CONCLUSIONS

Our study shows that APR following preoperative CRT exhibited more adverse oncologic outcomes compared with SPP. This result may be due to higher rates of CRM involvement in APR even with preoperative CRT. We suggest that sharp perineal dissection and wider cylindrical excision at the level of the anorectal junction are required to avoid CRM involvement and improve oncologic outcomes in patients who undergo APR following preoperative CRT.

Accuracy of endoscopic ultrasound to diagnose nodal invasion by rectal cancers: a meta-analysis and systematic review

BACKGROUND

Nodal staging in patients with rectal cancer predicts prognosis and directs therapy. Published data on the accuracy of endoscopic ultrasound (EUS) for diagnosing nodal invasion in patients with rectal cancer has been inconsistent.

AIM

To evaluate the accuracy of EUS in diagnosing nodal metastasis of rectal cancers.

METHOD

Study Selection Criteria: Only EUS studies confirmed by surgical histology were selected. Data Collection and Extraction: Articles were searched in Medline, Pubmed, and CENTRAL.

STATISTICAL METHOD

Pooling was conducted by both fixed-effects model and random-effects model.

RESULTS

The initial search identified 3610 reference articles in which 352 relevant articles were selected and reviewed. Data were extracted from 35 studies (N = 2732) that met the inclusion criteria. Pooled sensitivity of EUS in diagnosing nodal involvement by rectal cancers was 73.2% (95% confidence interval [95% CI] 70.6-75.6). EUS had a pooled specificity of 75.8% (95% CI 73.5-78.0). The positive likelihood ratio of EUS was 2.84 (95% CI 2.16-3.72), and negative likelihood ratio was 0.42 (95% CI 0.33-0.52). All the pooled estimates, calculated by fixed- and random-effect models, were similar. SROC curves showed an area under the curve of 0.79. The P for chi-squared heterogeneity for all the pooled accuracy estimates was >.10.

CONCLUSIONS

EUS is an important and accurate diagnostic tool for evaluating nodal metastasis of rectal cancers. This meta-analysis shows that the sensitivity and specificity of EUS is moderate. Further refinement in EUS technologies and diagnostic criteria are needed to improve the diagnostic accuracy.

[What do we know about the lymphatic drainage of the rectum?]

Lymph node (LN) involvement is one of the most significant prognostic factors of patients with rectal cancer. However, the distribution of rectal LN is not well known. The rectal LN are mainly located around the rectal arteries. In the mesorectum, the LN are mainly located posteriorly. The number of LN by patient varies considerably. Many reasons can explain this variability. Acquired factors such as infection, inflammation or metastatic involvement facilitate the detection of LN. In contrast, preoperative radiotherapy reduces the number and size of lymph nodes. The procedure of resection affects the number of LN harvested. Extensive lymphadenectomies increase the number of LN harvested. The technique used by pathologist has equally a major influence. The fat clearing method allows detection of a greater number of LN than manual dissection particularly for small LN. Toxicity of these solutions and a time-consuming process explain that fat clearing method is rarely used in clinical practice. Detection of rectal lymph nodes is difficult and tedious but is necessary for an accurate staging of patients with rectal cancer.

The predictive value of metabolic response to preoperative radiochemotherapy in locally advanced rectal cancer measured by PET/CT

BACKGROUND

To evaluate the value of positron emission tomography using fluorodeoxyglucose and computer tomography scan (FDG-PET/CT) for prediction of histopathological response of preoperative radiochemotherapy (RCTX) in patients with rectal carcinoma.

METHODS

Thirty patients with uT3 rectal carcinoma were examined by FDG-PET/CT at baseline, 14 days after initiation, and after completion of preoperative RCTX. The FDG decreases seen with PET scanning from baseline to day 14 (early metabolic response) and after completion of therapy (late metabolic response) were compared with histopathological tumor response. One patient denied surgery after RCTX.

RESULTS

The mean (+/-SD) reduction of tumor FDG uptake in histopathologically responding compared to non-responding tumors was -44.3% (+/-20.1%) versus -29.6% (+/-13.1%) (p = 0.085) at day 14 and -66.0% (+/-20.3%) versus -48.3% (+/-23.4%) (p = 0.040) after completion of RCTX. Best differentiation of histopathological tumor response was achieved by a cut-off value of 35% reduction of initial FDG uptake at day 14 and 57.5% after completion of therapy. Applying the cut-off values as a criterion for metabolic response, histopathological response was predicted with a sensitivity of 74% (14/19) at day 14 and 79% (15/19) after completion of therapy. The positive predictive value for early metabolic response was 82% (14/17) and for late metabolic response was 83% (15/18). Histopathological evidence of accumulated peritumoral inflammation cells was associated with a minor FDG decrease in five histopathologically responding patients, and influenced the results with negative predictive values of 58% (7/12) and 64% (7/11) at the early and late time points, respectively.

CONCLUSIONS

Metabolic response to a preoperative RCTX using FDG-PET/CT in rectal cancer patients can be correlated with histopathological response, but FDG uptake of peritumoral inflammation cells limited the results and led to false negative results.

Resection margins in modern rectal cancer surgery

At present, the preferred treatment for rectal cancer is low anterior resection with total mesorectal excision and sphincter preservation. Complete removal of the tumor's lymphatic and vascular pad with free resection margins has led to a reduction in rates of local recurrence and improved disease-specific survival. In addition to the distal and proximal margins from the tumor edge, for an optimal outcome, it is essential to consider distal mesorectal spread and the circumferential mesorectal margin.

Histopathological response to preoperative chemoradiation for resectable pancreatic adenocarcinoma: the French Phase II FFCD 9704-SFRO Trial

PURPOSE

This study suggests that pancreatic adenocarcinoma is a chemoradiosensitive tumor and that preoperative chemoradiation provides antitumoral effect associated with major histopathological response in 50% of patients and a high R0 resection rate. Evaluation of histopathological response to neoadjuvant therapy may serve as a surrogate marker for treatment efficacy and remains an active area of investigation.

OBJECTIVES

The chemoradiosensitive of pancreatic adenocarcinoma has not yet fully been assessed. The purpose of this study is to determine the efficacy of preoperative chemoradiation, measured by the impact on the R0 resection rate and the histopathological response rate in patients presenting with resectable pancreatic adenocarcinoma.

METHODS

Patients with localized, potentially resectable pancreatic adenocarcinoma were treated with 50 Gy irradiation combined with 5-fluorouracil by continuous infusion (300 mg . m(-2) . d(-1); day 1-5; week 1-5) and cisplatin (20 mg . m(-2) . d(-1); day 1-5 and day 29-33). Patients presenting with resectable disease at restaging, without metastatic dissemination, underwent surgical resection.

RESULTS

Forty-one patients were enrolled. Twenty-seven patients (67.5%) completed chemoradiation receiving at least 75% prescribed chemotherapy dose without grade 4 nonhematological toxicity. Twenty-six patients (63%) underwent surgical resection with curative intent and 21 (80.7%) had R0 resection. Thirteen of 26 specimens (50%) presented a major pathologic response with more than 80% of severely degenerative cancer cells. Complete pathologic response was observed in one specimen. Median survival time and 2-year survival rate were 9.4 months and 20% for the entire cohort. The local recurrence and 2-year survival rates were 4% and 32%, respectively, for the 26 operated patients.

CONCLUSIONS

This study suggests that some pancreatic adenocarcinomas are chemoradiosensitive and that preoperative chemoradiation provides antitumoral effect associated with major histopathological response in 50% of patients and a high R0 resection rate. Further research is needed to determine the biologic difference between responders and nonresponders, to evaluate the predictive value of treatment response parameters, and to optimize the chemoradiation regimen.

Management of rectal cancer: short- vs. long-course preoperative radiation

There is considerable debate on the optimum approach to neoadjuvant therapy in rectal cancer. This review of major published studies of short-course preoperative radiation and the more conventional approach of long-course neoadjuvant chemoradiation was undertaken in an effort to understand the potential advantages and disadvantages of each of these approaches. Studies were evaluated with regard to patient selection, clinical outcomes, and toxicities. Short-course preoperative radiation has shown a clear advantage over surgery alone in reducing local recurrence rates and improving survival of patients with rectal cancer. However, studies using short-course preoperative treatment have included a significant number of early (30%; Stage I/II) and more proximal cancers yet appear to have higher positive margin rates, higher abdominoperineal resection rates, and lower aggregate survival than patients treated with long-course neoadjuvant chemoradiation. Although long-course preoperative chemoradiation is associated with higher rates of reversible acute toxicity, there appears to be more significant and a higher rate of late gastrointestinal toxicity observed in short-course preoperative radiation studies. Patient convenience and lower cost of treatment, however, can be a significant advantage in using a short-course treatment schedule. Selective utilization of either of these approaches should be based on extent of disease and goals of treatment. Patients with distal cancers or more advanced disease (T3/T4) appear to have better outcomes with neoadjuvant chemoradiation, especially where downstaging of disease is critical for more complete surgical resection and sphincter preservation.

Predictors of disease-free survival in rectal cancer patients undergoing curative proctectomy

OBJECTIVE

To identify the factors that affect the disease-free survival (DFS) of rectal cancer patients.

METHOD

Patients from an IRB approved rectal cancer database were reviewed (1990-2000). All patients underwent either abdominoperineal resection or low anterior resection using total mesorectal excision with curative intent. Univariate and multivariate analyses were performed to analyse the factors that influenced DFS.

RESULTS

A total of 304 patients were reviewed (mean age 64, 52% male). Seventy-seven per cent of patients received neoadjuvant therapy (28.6% short-course radiation therapy (RT), 35.5% long-course RT, 12.5% chemo-RT). The radial margin was involved with tumour in 5.2% of patients (final pathology). The overall survival rate was 85.2% with a mean follow-up time of 33 +/- 26 months. The mean time to death was 34.8 +/- 26.8 months. Local recurrence (+/- distant recurrence) occurred in 4%. Anastomotic leaks occurred in 3.6% of patients. Overall pathologic stage, pathologic T stage, nodal status, the use of adjuvant chemotherapy, tumour fixation, involvement of the radial margin, the presence of mucin, and lymphatic and perineural invasion (PNI) were predictors of DFS by univariate analysis. Of note, anastomotic leaks and obstructing cancers did not influence DFS. Using multivariate analysis with backward elimination, overall pathologic stage, radial margin status, adjuvant chemotherapy, and PNI predicted the DFS.

CONCLUSION

Major predictors of DFS in rectal cancer are the overall pathologic stage, adjuvant chemotherapy, radial margin status and PNI. Radial margin status may be a marker of tumour aggressiveness and should be considered in deciding on adjuvant chemotherapy.

A simplified tumor regression grade correlates with survival in locally advanced rectal carcinoma treated with neoadjuvant chemoradiotherapy

BACKGROUND

Locally advanced rectal cancer is frequently treated with neoadjuvant chemoradiotherapy to reduce local recurrence and possibly improve survival. The tumor response to chemoradiotherapy is variable and may influence the prognosis after surgery. This study assessed tumor regression and its influence on survival in patients with rectal cancer treated with chemoradiotherapy followed by curative surgery.

METHODS

One hundred twenty-six patients with locally advanced rectal cancer (T3/T4 or N1/N2) were treated with chemoradiotherapy followed by total mesorectal excision. Patients received long-course radiotherapy (50 Gy in 25 fractions) in combination with 5-flourouracil over 5 weeks. By means of a standardized approach, tumor regression was graded in the resection specimen using a 3-point system related to tumor regression grade (TRG): complete or near-complete response (TRG1), partial response (TRG2), or no response (TRG3).

RESULTS

The 5-year disease-free survival was 72% (median follow-up 37 months), and 7% of patients had local recurrence. Chemoradiotherapy produced downstaging in 60% of patients; 21% of patients experienced TRG1. TRG1 correlated with a pathological T0/1 or N0 status. Five-year disease-free survival after chemoradiotherapy and surgery was significantly better in TRG1 patients (100%) compared with TRG2 (71%) and TRG3 (66%) (P = .01).

CONCLUSION

Tumor regression grade measured on a 3-point system predicts outcome after chemoradiotherapy and surgery for locally advanced rectal cancer.

Preoperative versus postoperative radiotherapy for locally advanced gastroesophageal junction and proximal gastric cancers: a comparison of normal tissue radiation doses

Locoregional relapse occurs in over half of gastric cancer patients who undergo potentially curative resection. Adjuvant chemoradiation reduces locoregional relapse, but often requires irradiating large fields and is limited by poor patient tolerance. This study explores the potential dosimetric benefit in reducing the radiation dose to normal structures by treating gastroesophageal (GE) junction/proximal gastric cancers with preoperative rather than adjuvant radiotherapy. Five cases of GE junction/proximal gastric cancer patients treated postoperatively with curative intent were selected. The actual target contours were then modified to reflect hypothetical target volumes which would have been used had the patients been treated preoperatively. Hypothetical preoperative treatment plans were generated for each patient based on these modified contours. The hypothetical preoperative treatment plans were then compared to the actual postoperative plans with respect to dose-volume parameters including lung mean dose, lung V20, heart V20 and V30, and mean doses to abdominal structures. Target volumes were smaller with preoperative treatment, with an average reduction of 23%. Comparative dose-volume histogram (DVH) analysis showed the resultant composite lung doses were reduced in the preoperative plans by 50-79%. In all patients, the proportion of lungs receiving at least 20 Gy (V20) was substantially reduced using preoperative treatment (1.9% vs. 9.7% in the 3-D conformal patient; mean of 3.1% vs. 17.6% in the intensity modulated radiation therapy patients). Likewise, the volume of heart receiving at least 30 Gy was dramatically reduced in all preoperative plans (15.8% vs. 35.4%). Doses to the kidneys, liver and spinal cord were comparable in both approaches. Preoperative treatment of GE junction and proximal gastric cancer patients offers the potential to decrease the radiation dose received by normal thoracic structures.