Pre-operative radiochemotherapy of locally advanced rectal cancer

Bowel dysfunction after treatment for rectal cancer

INTRODUCTION

Rectal cancer is a common disease in Western populations. Improved treatment modalities have resulted in increased survival and tumour control. With increasing survival there is a growing need for knowledge about the long-term side effects and functional results after the treatment.

AIM

To describe the long-term functional outcome in patients treated for rectal cancer through a systematic review of the current literature and to provide an outline of the promising developments within this area.

RESULTS

Standard resectional surgery with loss of the rectal reservoir function results in poor functional results in up to 50-60% of the patients. New methods of surgery including the construction of a neoreservoir and improvement of the technique for local excision have been developed to minimize the functional disturbances without compromising the oncological result. The addition of chemo and/or radiotherapy approximately doubles the risk of poor functional results. During the last decades the techniques for chemo/radiotherapy has been markedly improved with a positive impact on functional outcome. New methods for treatment of functional disturbances e.g. bowel irrigation and sacral nerve stimulation are currently under development.

PERSPECTIVES

To improve the functional outcome in this growing patient population several approaches can be taken. The primary cancer treatment must be improved by minimizing the surgical trauma and optimizing the imaging and radiation techniques. Population screening should be considered in order to find the cancers at an earlier stage, hereby increasing the proportion of patients eligible for local excision without the need for chemo/irradiation. All patients recovering from rectal resection should be examined and registered systematically regarding their functional results and treatment should be offered to the severely affected patients. More studies are still needed to evaluate the efficacy of irrigation and nerve stimulation in this patient group.

Capecitabine vs continuous infusion 5-FU in neoadjuvant treatment of rectal cancer. A retrospective review

BACKGROUND

Standard therapy for locally advanced rectal cancer (LARC) is concurrent neo-adjuvant chemo-radiation using infusional 5-fluorouracil (CIV-5-FU). Capecitabine (CAP) offers a convenient oral replacement for CIV-5-FU. There is no randomized trial comparing infusional 5-FU to capecitabine. We retrospectively compared the safety and efficacy of CAP-based regimens with well-established CIV-5-FU-based regimens in LARC.

MATERIALS AND METHODS

We collected published data on 542 patients treated on either CIV-5-FU (197) or CAP (345) with concurrent radiation (external radiation treatment, XRT) for LARC. This included Phase I or II studies published or available from Pubmed. Safety was assessed by determining proportion of patients who experienced grade III/IV adverse effects. Efficacy was assessed by determining pathological complete response (pCR). Chi-square tests were used to compare the two regimens. A P value less than 0.05 was considered statistically significant. Statistical tests were further corrected for multiplicity using the method of Benjamini and Yekutieli (Ann Stat, 29(4):1165-1188, 2001).

RESULTS

pCR was significantly higher in patients getting CAP vs CIV-5-FU (25 vs 13%; P = 0.008,.P adj = 0.034). Both regimens were generally well tolerated. There was no grade IV toxicity reported. Grade III hand foot syndrome was more common in the CAP group, and grade III diarrhea was more common in the CIV group.

CONCLUSIONS

CAP when compared to CIV seems to have superior efficacy with reasonable toxicities. It is reasonable to treat LARC with CAP + XRT.

Neoadjuvant chemoradiation versus hyperfractionated accelerated radiotherapy in locally advanced rectal cancer

BACKGROUND

Neoadjuvant therapy is increasingly used in resectable locally advanced rectal cancer. The exact role of the addition of chemotherapy is not established. We compared neoadjuvant therapy using chemoradiation (CRT) or hyperfractionated accelerated radiotherapy (HART).

METHODS

Clinical, pathological, and survival data were obtained from patients with resectable stage II or III rectal cancer within 7 cm from the anal verge. A group of 50 patients was treated with a preoperative dose of 41.6 Gy of radiotherapy (RT) in two daily fractions of 1.6 Gy over 13 days immediately followed by surgery (HART). A second group of 96 patients received 45 Gy of conventionally fractionated RT in 25 daily fractions of 1.8 Gy combined with 5-fluorouracil-based chemotherapy followed by surgery within 4 to 6 weeks (CRT). Both groups were compared in terms of morbidity, pathological downstaging, local recurrence, and survival.

RESULTS

Both groups were comparable in terms of preoperative clinicopathological variables. The mean distance from the anal verge was 5.8 cm (HART) versus 4.9 cm (CRT). Sphincter preservation was possible in 74% (HART) versus 83.5% (CRT) of patients (P = .013). The clinical anastomotic leak rate was 2% (HART) versus 2.2% (CRT). Pathological complete response was observed in 4% (HART) versus 18% (CRT) of the resected specimens (P = .002). A pelvic recurrence developed in 6% (HART) versus 4.4% (CRT) of patients (P = .98). Overall 5-year survival was 58% (HART) versus 66% (CRT) (P = .19); disease-free 5-year survival was 51% (HART) versus 62% (CRT) (P = .037).

CONCLUSIONS

Compared with preoperative HART followed by immediate surgery, preoperative CRT followed by a 6-week waiting period enhances pathological response and increases sphincter preservation rate. This could be explained by the addition of chemotherapy or the longer interval between neoadjuvant therapy and surgery. No statistically significant difference was observed in local control or overall survival.

Three-dimensional conformal radiotherapy combined with FOLFOX4 chemotherapy for unresectable recurrent rectal cancer

AIM: To investigate the effect of three-dimensional conformal radiotherapy (3-DCRT) in combination with FOLFOX4 chemotherapy for unresectable recurrent rectal cancer.

METHODS: Forty-eight patients with unresectable recurrent rectal cancer were randomized and treated by 3-DCRT or 3-DCRT combined with FOLFOX4 chemotherapy between September 2001 and October 2003. For the patients without prior radiation history, the initial radiation was given to the whole pelvis by traditional methods with tumor dose of 40 Gy, followed by 3-DCRT for the recurrent lesions to the median total cumulative tumor dose of 60 Gy (range 56-66 Gy); for the post-radiation recurrent patients, 3-DCRT was directly given for the recurrent lesions to the median tumor dose of 40 Gy (36-46 Gy). For patients in the study group, two cycles chemotherapy with FOLFOX4 regimen were given concurrently with radiotherapy, with the first cycle given simultaneously with the initiation of radiation and the second cycle given in the fifth week for patients receiving conventional pelvis radiation or given in the last week of 3-DCRT for patients receiving 3-DCRT directly. Another 2-4 cycles (average 3.6 cycles) sequential FOLFOX4 regimen chemotherapy were given to the patients in the study group, beginning at 2-3 wk after chemoradiation. The outcomes of symptoms relieve, tumor response, survival and toxicity were recorded and compared between the study group and the control group.

RESULTS: For the study group and the control group, the pain-alleviation rates were 95.2% and 91.3% (P > 0.05); the overall response rates were 56.5% and 40.0% (P > 0.05); the 1-year and 2-year survival rates were 86.9%, 50.2% and 80.0%, 23.9%, with median survival time of 25 mo and 16 mo (P < 0.05); the 2-year distant metastasis rates were 39.1% and 56.0% (P = 0.054), respectively. The side effects, except peripheral neuropathy which was relatively severer in the study group, were similar in the the two groups and well tolerated.

CONCLUSION: Three-dimensional conformal radio-therapy combined with FOLFOX4 chemotherapy for unresectable recurrent rectal cancer is a feasible and effective therapeutic approach, and can reduce distant metastasis rate and improve the survival rate.

Pre-operative combined modality therapy in the management of locally advanced rectal cancer

AIMS

To review the use of pre-operative combined modality therapy (CMT, chemotherapy with radiotherapy) in the management of resectable rectal cancer.

METHODS

A systematic search was performed on pre-operative CMT and rectal cancer. Additional information was retrieved from hand searching the literature and from relevant congress proceedings. We addressed the following issues: Phase II studies of pre-operative CMT, pre-operative radiotherapy (RT) alone vs pre-operative CMT, pre-operative vs post-operative CMT, functional outcome and pathologic downstaging after CMT, prediction and importance of complete response to CMT.

RESULTS

Pre-operative CMT results in an average pathological complete response (pCR) rate of 18.5% in Phase II studies. Compared with pre-operative RT alone, the addition of CT significantly improves tumour response but not overall survival while acute toxicity increases and the effect on sphincter preservation is at present unclear. Pre-operative CMT has been proven to be superior to post-operative CMT in a German multicenter randomized trial. The scarce available data suggest that the addition of CT might worsen anorectal function compared to pre-operative RT alone. Although a significant pathological response is prognostically favourable, the clinical and imaging tools available at present do not allow to accurately predict pCR in clinical complete responders confirming the indication for surgery in this subgroup.

CONCLUSIONS

Pre-operative CMT enhances tumour response and could therefore, have a role in patients with possibly invaded resection margins or low lying cancers, although both acute toxicity and anorectal function are worse compared to RT alone. The final results of ongoing randomized trials will more accurately establish the role of pre-operative CMT in resectable rectal cancer patients.

Apoptosis induced by preoperative oral 5’-DFUR administration in gastric adenocarcinoma and its mechanism of action

AIM: To study the apoptosis induced by preoperative oral 5’-DFUR administration in gastric adenocarcinoma and its mechanism of action.

METHODS: Sixty gastric cancer patients were divided randomly into three groups (20 each group) before operation: group one: 5’-DFUR oral administration at the dose of 800-1200mg/d for 3 - 5 d, group two: 500mg 5-FU + 200 mg/d CF by venous drip for 3 - 5 d, group three (control group). One or two days after chemotherapy, the patients were operated. Fas/FasL, PD-ECGF and PCNA were examined by immunohistochemistry and apoptotic tumor cells were detected by in situ TUNEL method. Fifty-four patients received gastrectomy, including 12 palliative resections and 42 radical resections. Six patients were excluded. Finally 18 cases in 5’-DFUR group, 16 cases in CF + 5-FU group, and 20 cases in control group were analyzed.

RESULTS: There was no significant difference in patient mean age, gender, white blood cell count, haematoglobin (HB), thromboplastin, perioperative complication incidence, radical or palliation resection, invasion depth (T), lymphonode involvement (N), metastasis (M) and TNM staging among the three groups. However, the PCNA index (PI) in 5’-DFUR group (40.51 ± 12.62) and 5-FU + CF group (41.12 ± 15.26) was significantly lower than that in control group (58.33 ± 15.69) (F = 9.083, P = 0.000). The apoptotic index (AI) in 5’-DFUR group (14.39 ± 9.49) and 5-FU + CF group (14.11±9.68) was significantly higher than that in control group (6.88 ± 7.37) (F = 4.409, P = 0.017). The expression rates of Fas and FasL in group one and group three were 66.7% (12/18) and 50% (9/18), 43.8% (7/16) and 81.3% (13/16), 45.0% (9/20) and 85% (17/20), respectively. The expression rate of FasL in 5’-DFUR group was significantly lower than that in the other two groups (χ²=6.708, P = 0.035). Meanwhile, the expression rate of PD-ECGF was significantly lower in 5’-DFUR group (4/18，28.6%) than in CF + 5-FU group（9/16，56.3%）and control group (13/20，65.0%) (χ²= 7.542, P = 0.023). The frequency of Fas expression was significantly correlated with palliative or radical resection (χ²= 7.651, P = 0.006), invasion depth (χ²= 8.927, P = 0.003), lymphatic spread (χ²= 4.488, P = 0.034) and UICC stages (χ²= 8.063, P = 0.045) respectively. By the end of March 2005, 45 patients were followed up. The 0.5-, 1-, 2-, 3-year survival rates were 96%，73%，60%，48%, respectively, which were related with T, N, M and Fas expression, but not with PD-ECGF and FasL expression.

CONCLUSION: Preoperative oral 5’-DFUR administration may induce apoptosis of gastric carcinoma cells and decrease tumor cell proliferation index, but cannot improve the prognosis of patients with gastric cancer. Down-regulation of FasL and PD-ECGF expression mediated by 5’-DFUR may be one of its anti-cancer mechanisms. Fas expression correlates with the progression of gastric carcinoma and may be an effective prognostic factor.

Anatomic pathology of tumor cell spread through lymph nodes in the mesorectum of rectal cancer

AIM: To investigate the size, distribution, and pattern of metastases and micrometastases of lymph nodes (LNs) within the mesorectum of rectal cancer.

METHODS: All rectal cancer specimens obtained by total mesorectal excision were treated with lymph node revealing solution to retrieve all LNs, which were detected with a combination use of haematoxylin and eosin staining and immunohistochemical (IHC) staining with an antibody against cytokeratin 20.

RESULTS: A total of 548 LNs in 31 specimens were harvested, with 17.7 nodes per case. 153 nodes (27.9%) in 27 patients (87.1%) were found positive by routine pathological examination and IHC staining. Of all the nodes retrieved, nodes <0.5 cm numbered 366 (66.8%) with 91 (59.5%) positive. Among the 27 metastasized cases, there were 15 cases whose tumors were located in the back wall of the rectum, in which 78 nodes were detected positive with 75 nodes along the superior rectal artery. In the other 12 cases with tumors positioned in the lateral wall, 75 nodes were diagnosed positive, with 37 nodes, 8 nodes around the branch of superior rectal artery and middle rectal artery on tumor side, and 9 nodes, 0 nodes on the opposite side, respectively.

CONCLUSION: The majority of tumor positive LNs in the mesorectum are <0.5 cm in diameter. LNs within the mesorectum are distributed mainly along major supplying vessels with around the superior rectal artery most. The pattern of lymphatic spread of rectal cancer has close relationships with tumor location in the rectal wall. Tumors in the posterior wall may spread in both sides of the mesorectum simultaneously, while tumors localized in one lateral wall tend to metastasize preferably to LNs in the mesorectum of tumor side.

Comparative evaluation of immune response after laparoscopical and open total mesorectal excisions with anal sphincter preservation in patients with rectal cancer

AIM: The study of immune response of open versus laparoscopical total mesorectal excision with anal sphincter preservation in patients with rectal cancer has not been reported yet. The dissected retroperitoneal area that contacts directly with carbon dioxide is extensive in laparoscopic total mesorectal excision with anal sphincter preservation surgery. It is important to clarify whether the immune response of laparoscopic total mesorectal excision with anal sphincter preservation (LTME with ASP) in patients with rectal cancer is suppressed more severely than that of open surgery (OTME with ASP). This study was designed to compare the immune functions after laparoscopic and open total mesorectal excision with anal sphincter preservation for rectal cancer.

METHODS: This study involved 45 patients undergoing laparoscopic (n = 20) and open (n = 25) total mesorectal excisions with anal sphincter preservation for rectal cancer. Serum interleukin-2 (IL-2), interleukin-6 (IL-6), tumor necrosis factor α (TNF_α) were assayed preoperatively and on days 1 and 5 postoperatively. CD3⁺ and CD56⁺ T lymphocyte count, CD3^- and CD56⁺ natural killer cell (NK) count and immunoglobulin (IgG/IgM/IgA) were assayed preoperatively and on day 5 postoperatively. The numbers of CD3⁺ and CD56⁺ T lymphocytes and CD3^- and CD56⁺ NK cells were counted using flow cytometry. An enzyme-linked immunosorbent assay (ELISA) was used for IL-2, IL-6 and TNF_α determination. And IgG, IgM, and IgA were assayed using immunonephelometry.

RESULTS: The demographic data of the two groups had no difference. The preoperative levels of CD3⁺ and CD56⁺ T lymphocyte count, CD3^- and CD56⁺ NK count, serum IgG, IgM, IgA, IL-2, IL-6 and TNF_α also had no significant difference in the two groups (P > 0.05). The CD3⁺ and CD56⁺ T lymphocyte counts had no obvious changes after surgery in laparoscopic (d = -0.79% ± 3.83%) and open (d = 0.42% ± 2.09%) groups. The CD3^- and CD56⁺ NK counts were decreased postoperatively in both laparoscopic (d = -7.23% ± 11.33%) and open (d = -9.21% ± 13.93%) groups. The differences of the determined values of serum IgG, IgM and IgA on the fifth day after operation subtracted those before operation were -2.56 ± 2.14 g/L, -252.35 ± 392.94 mg/L, -506.15 ± 912.24 mg/L in laparoscopic group, and -1.81 ± 2.10 g/L, -282.72 ± 356.75 mg/L, -252.20 ± 396.28 mg/L in open group, respectively. The levels of IL-2 were decreased after operation in both groups. However, the levels of IL-6 were decreased after laparoscopic surgery (d₁ = -23.14 ± 263.97 ng/L and d₅ = -40.08 ± 272.03 ng/L), and increased after open surgery (d₁ = 27.38 ± 129.14 ng/L and d₅ = 21.67 ± 234.31 ng/L). The TNF_α levels were not elevated after surgery in both groups. There were no significant differences in the numbers of CD3⁺ and CD56⁺ T lymphocytes and CD3^- and CD56⁺ NK cells, the levels of IgG, IgM, IgA, IL-2, IL-6 and TNF_α between the two groups (P > 0.05).

CONCLUSION: There are no differences in immune responses between the patients having laparoscopic total mesorectal excision with anal sphincter preservation and those undergone open surgery for rectal cancer.

Differentially expressed proteins of gamma-ray irradiated mouse intestinal epithelial cells by two-dimensional electrophoresis and MALDI-TOF mass spectrometry

AIM: To identify the differentially expressed proteins involved in ionizing radiation in mice and to explore new ways for studying radiation-related proteins.

METHODS: Bal B/c mice grouped as sham-irradiation, 3 h and 72 h irradiation were exposed to 9.0Gy single dose of γ-irradiation. Intestinal epithelia were isolated from mice, and total proteins were extracted with urea containing solution. A series of methods were used, including two-dimensional electrophoresis, PDQuest 2-DE software analysis, peptide mass fingerprinting based on matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS) and SWISS-PROT database searching, to separate and identify the differential proteins. Western blotting and RT-PCR were used to validate the differentially expressed proteins.

RESULTS: Mouse intestine was severely damaged by 9.0 Gy γ-irradiation. Image analysis of two-dimensional gels revealed that averages of 638 ± 39, 566 ± 32 and 591 ± 29 protein spots were detected in 3 groups, respectively, and the majority of these protein spots were matched. About 360 protein spots were matched between normal group and 3 h irradiation group, and the correlation coefficient was 0.78 by correlation analysis of gels. Also 312 protein spots matched between normal group and 72 h irradiation group, and 282 protein spots between 3 h and 72 h irradiation groups. Twenty-eight differential protein spots were isolated from gels, digested with trypsin, and measured with MALDI-TOF-MS. A total of 25 spots yielded good spectra, and 19 spots matched known proteins after database searching. These proteins were mainly involved in anti-oxidation, metabolism, signal transduction, and protein post-translational processes. Western-blotting confirmed that enolase was up-regulated by γ-irradiation. Up-regulation of peroxiredoxin I was verified by applying RT-PCR technique, but no change occurred in Q8VC72.

CONCLUSION: These differentially expressed proteins might play important roles when mouse intestine was severely injured by γ-irradiation. It is suggested that differential proteomic analysis may be a useful tool to study the proteins involved in radiation damage of mouse intestinal epithelia.