The rationale to switch from postoperative hyperfractionated accelerated radiotherapy to preoperative hyperfractionated accelerated radiotherapy in rectal cancer

Neoadjuvant hyperfractionated accelerated radiotherapy plus concomitant 5-fluorouracil infusion in locally advanced rectal cancer: A phase II study

AIM

To evaluate the efficacy and tolerability of neoadjuvant hyperfractionated accelerated radiotherapy (HART) and concurrent chemotherapy in patients with locally advanced infraperitoneal rectal cancer.

METHODS

A total of 30 patients with histopathologically confirmed T2-3/N0+ infraperitoneal adenocarcinoma of rectum cancer patients received preoperative 42 Gy/1.5 Gy/18 days/bid radiotherapy and continuous infusion of 5-fluorouracil (325 mg/m2). All patients were operated 4-8 wk after neoadjuvant concomitant therapy.

RESULTS

In the early phase of treatment, 6 patients had grade III-IV gastrointestinal toxicity, 2 patients had grade III-IV hematologic toxicity, and 1 patient had grade V toxicity due to postoperative sepsis during chemotherapy. Only 1 patient had radiotherapy-related late side effects, i.e., grade IV tenesmus. Complete pathological response was achieved in 6 patients (21%), while near-complete pathological response was obtained in 9 (31%). After a median follow-up period of 60 mo, the local tumor control rate was 96.6%. In 13 patients, distant metastasis occurred. Disease-free survival rates at 2 and 5 years were 63.3% and 53%, and corresponding overall survival rates were 70% and 53.1%, respectively.

CONCLUSION

Although it has excellent local control and complete pathological response rates, neoadjuvant HART concurrent chemotherapy appears to not be a feasible treatment regimen in locally advanced rectal cancer, having high perioperative complication and intolerable side effects. Effects of reduced 5-fluorouracil dose or omission of chemotherapy with the aim of reducing toxicity may be examined in further studies.

Pre-operative hyperfractionated concurrent radiochemotherapy for locally advanced rectal cancers: a phase II clinical study

OBJECTIVE

The study was prospectively designed as a single-arm, single-institution prospective trial of pre-operative concomitant hyperfractionated radiotherapy (HART) with co-administration of chemotherapy based on 5-fluorouracil (5FU) in patients with T2/N+ or T3/any N resectable mid-low primary rectal cancer. The aim of the study was to assess the safety and efficacy of accelerated HART with concurrent 5FU-based chemotherapy in patients with locally advanced rectal cancer.

METHODS

Patients with resectable locally advanced (≥T3 or N+) rectal cancer were eligible. The patients received total dose 42 Gy in 28 fractions of 1.5 Gy, two times daily, with at least 8 h of interval, with concurrent chemotherapy: 325 mg m^-2 of 5FU (bolus) on Days 1-3 and Days 16-18 (except for cN0 patients for whom only one cycle on Days 1-3 was prescribed). The primary end point included tolerance, post-operative complication rate and pathological response rate. The secondary end points included locoregional relapse-free survival, metastasis-free survival and overall survival.

RESULTS

Out of 53 enrolled patients; 2 did not undergo surgery. Of the 51 patients evaluable for pathological response, there were 8 (15.6%), 20 (39.3%), 18 (35.3%) and 5 (9.8%) patients with tumour regression grade 0, 1, 2 and 3, respectively. Downstaging of the primary tumour and lymph nodes was observed in 22 (43%) and 25 (49%) patients, respectively. The primary tumour ypCR (ypT0) rate was 15% (8/51). The nodal ypCR rate for cN+ patients was 60% (21/35). The total ypCR (ypT0N0M0) rate was 11% (6/51). Toxicity included: Grade 3 diarrhoea (4/51, 7.8%), Grade 2 diarrhoea (22/51, 43.1%), Grade 2 leukopenia (7/51, 13.7%), Grade 2 neutropenia (6/51, 11.7%) and Grade 1 thrombocytopenia (3/51, 5.9%). No Grade 4 toxicity was reported. Nine patients (18%) presented with post-operative complications (during the 3 months after surgery). There were 6 locoregional relapses (11.8%) and distant metastasis occurred in 11 patients (21.6%). The 2-year cumulative locoregional relapse-free survival, metastasis-free survival and overall survival was 87%, 79% and 89%, respectively.

CONCLUSION

The proposed pre-operative HART with co-administration of 5FU had acceptable toxicity profile and provided satisfactory rate of ypCR. This created rationale to initiate a Phase III randomized study that was registered under ClinicalTrials.gov Identifier: NCT01814969. Advances in knowledge: The results of this research show that responders to pre-operative radiochemotherapy have favourable outcome. Tumour regression grade as prognostic clinical feature holds the promise of better classifying patients at high risk of local and systemic recurrence and this issue may be an interesting objective for future research.

Moderately Low Alpha/Beta Ratio for Rectal Cancer May Best Explain the Outcome of Three Fractionation Schedules of Preoperative Radiotherapy

PURPOSE

To estimate the alpha/beta ratio for rectal cancer according to the outcome of three fractionation schedules of preoperative radiotherapy.

METHODS AND MATERIALS

Between 1996 and 2002, 168 patients with locally advanced rectal cancer were treated as follows: 53 patients received 25 Gy in 5 Gy per fraction, 45 received 30 Gy in 3.0 Gy per fraction, and 70 were treated with accelerated hyperfractionation (42 Gy, 1.5 Gy per fraction, given twice daily). No patients received concurrent chemotherapy. The clinical characteristics of the groups were comparable. Surgery was performed shortly after radiotherapy. Crude data on locoregional tumor control were fitted directly using a linear-quadratic model, and the actuarial data were analyzed using Cox model.

RESULTS

A linear-quadratic model provided an alpha estimate of 0.339 (SE 0.115) and beta estimate of 0.067 (SE 0.027), which resulted in an alpha/beta ratio of 5.06 Gy (95% confidence interval -0.1 to 10.3). In all three schemes the overall radiation treatment time was short, which limits the rationales for incorporating time effect into the model. If, however, time was incorporated the alpha/beta ratio was 11.1 Gy and the dose increment required to compensate for repopulation was 0.15 Gy/day. The actuarial analysis provided similar alpha/beta estimates.

CONCLUSION

Although because of the retrospective character of the study, nonrandomized selection of fractionation schedule, and uncontrolled quality of surgery the present results can be regarded as hypothesis generating only, the control rates obtained in the pelvis are consistent with a moderately low alpha/beta ratio for rectal cancer.

Effect of timing of surgery on survival after preoperative hyperfractionated accelerated radiotherapy (HART) for locally advanced rectal cancer (LARC): is it a matter of days?

We intend to analyse retrospectively whether the time interval ("gap duration" = GD) between preoperative radiotherapy and surgery in locally advanced rectal cancer (LARC) has an impact on overall survival (OS), cancer specific survival (CSS), disease free survival (DFS) and local control (LC). Two hundred seventy nine patients with LARC were entered in Trial 93-01 (hyperfractionated accelerated radiotherapy 41.6 Gy/26 Fx BID) shortly followed by surgery. From these 250 patients are fully assessable. The median GD of 5 days was used as a discriminator. The median follow-up for all patients was 39 months. GD > 5 days was a significant discriminator for actuarial 5-years OS (69% vs 47%, p = 0.002), CSS (82% vs 57%, p = 0.0007), DFS (62% vs 41%, p = 0.0003) but not for LC (93% vs 90%, p = non-significant). In multivariate analysis, the following factors independently predict outcome; for OS: age, GD, circumferential margin (CM) and nodal stage (ypN); for CSS: GD, ypN and vascular invasion (VI); for DFS: CEA, distance to anal verge, GD, ypN and VI; for LC: CM only. Gap duration predicts survival outcome but not local control. The patients submitted to surgery after a median delay of more than 5 days had a significantly better outcome.

Usefulness of two independent histopathological classifications of tumor regression in patients with rectal cancer submitted to hyperfractionated pre-operative radiotherapy

AIM: To assess the usefulness of two independent histopathological classifications of rectal cancer regression following neo-adjuvant therapy.

METHODS: Forty patients at the initial stage cT3NxM0 submitted to preoperative radiotherapy (42 Gy during 18 d) and then to radical surgical treatment. The relationship between “T-downstaging” versus regressive changes expressed by tumor regression grade (TRG 1-5) and Nasierowska-Guttmejer classification (NG 1-3) was studied as well as the relationship between TRG and NG versus local tumor stage ypT and lymph nodes status, ypN.

RESULTS: Complete regression (ypT0, TRG 1) was found in one patient. “T-downstaging” was observed in 11 (27.5%) patients. There was a weak statistical significance of the relationship between “T-downstaging” and TRG staging and NG stage. Patients with ypT1 were diagnosed as TRG 2-3 while those with ypT3 as TRG5. No lymph node metastases were found in patients with TRG 1-2. None of the patients without lymph node metastases were diagnosed as TRG 5. Patients in the ypT1 stage were NG 1-2. No lymph node metastases were found in NG 1. There was a significant correlation between TRG and NG.

CONCLUSION: Histopathological classifications may be useful in the monitoring of the effects of hyperfractionated preoperative radiotherapy in patients with rectal cancer at the stage of cT3NxM0. There is no unequivocal relationship between “T-downstaging” and TRG and NG. There is some concordance in the assessment of lymph node status with ypT, TRG and NG. TRG and NG are of limited value for the risk assessment of the lymph node involvement.

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.

Phase II Trial of Preoperative Chemoradiation With a Hyperfractionated Radiation Boost in Locally Advanced Rectal Cancer

PURPOSE

The purpose of this phase II study was to prospectively determine the efficacy of preoperative chemoradiation with a hyperfractionated (Hfx) RT boost to 61.8 Gy in locally advanced rectal cancer.

METHODS

Eligibility stipulated that the primary lesion had to be either T4; or T3 and >4 cm or 40% of the bowel circumference. Radiation (RT) consisted of 45 Gy to the pelvis (1.8 Gy per fraction) followed by 1.2 Gy twice daily (to the gross tumor volume) to a total RT dose of 61.8 Gy. There was 5-FU infused at 1 g/m2/24 hours for 4 days during the 1st and 6th weeks of RT (concurrent with the Hfx boost). Surgical resection was planned 4 to 6 weeks later. Adjuvant chemotherapy (bolus 5-FU/leucovorin) was scheduled for 4 cycles at 28-day intervals.

RESULTS

There were 22 patients, ages 22 to 81 years (median, 64) enrolled in the study. Of the 20 patients evaluable for response, 10 (50%) had evidence of clinical downstaging and 5 patients (25%) had > or =90% fibrosis in the resected specimen. With a median f/u of 40 months (7-158), the 4 years actuarial rate for all patients (n = 22) of OS was 64%, of DFS 62%, and of LC 84%. 3/21 patients (14%) had positive margins, all of whom developed a local failure (P < 0.001).

CONCLUSION

This regimen of high dose preoperative chemoRT with a Hfx RT boost (to 61.8 Gy) in patients with bulky, locally advanced rectal cancer results in clinical downstaging in half of the patients with significant fibrosis in the operative specimen.

CPT-11 and concomitant hyperfractionated accelerated radiotherapy induce efficient local control in rectal cancer patients: results from a phase II

Patients with rectal cancer are at high risk of disease recurrence despite neoadjuvant radiochemotherapy with 5-Fluorouracil (5FU), a regimen that is now widely applied. In order to develop a regimen with increased antitumour activity, we previously established the recommended dose of neoadjuvant CPT-11 (three times weekly 90 mg m⁻²) concomitant to hyperfractionated accelerated radiotherapy (HART) followed by surgery within 1 week. Thirty-three patients (20 men) with a locally advanced adenocarcinoma of the rectum were enrolled in this prospective phase II trial (1 cT2, 29 cT3, 3 cT4 and 21 cN+). Median age was 60 years (range 43–75 years). All patients received all three injections of CPT-11 and all but two patients completed radiotherapy as planned. Surgery with total mesorectal excision (TME) was performed within 1 week (range 2–15 days). The preoperative chemoradiotherapy was overall well tolerated, 24% of the patients experienced grade 3 diarrhoea that was easily manageable. At a median follow-up of 2 years no local recurrence occurred, however, nine patients developed distant metastases. The 2-year disease-free survival was 66% (95% confidence interval 0.48–0.83). Neoadjuvant CPT-11 and HART allow for excellent local control; however, distant relapse remains a concern in this patient population.

A pilot study of accelerated preoperative hyperfractionated pelvic irradiation with or without low-dose preoperative prophylactic liver irradiation in patients with locally advanced rectal cancer

BACKGROUND AND PURPOSE

To evaluate the feasibility of low-dose preoperative prophylactic liver irradiation (PLI) combined with preoperative accelerated hyperfractionated pelvic irradiation (HART) in patients with locally advanced rectal cancer.

PATIENTS AND METHODS

Between 1999 and 2003 62 patients were enrolled: 38 (61%) received HART and 24 (39%) HART+PLI. The pelvis was irradiated twice a day, with a minimal interfraction interval of 6h: the total dose of 42 Gy was given in 1.5 Gy per fractions over 18 days. The PLI (14 Gy in 10 daily fractions of 1.4 Gy) was given simultaneously with the morning fraction of HART. Twenty patients (32%), including 7 in PLI group, received 5-Fu based postoperative chemotherapy.

RESULTS

In general, acute normal tissue reactions appeared tolerable irrespectively of PLI. Six to twelve months after completion of combined therapy the mean ALAT levels in patients treated with HART alone (25 pts), HART+chemotherapy (13 pts), HART+PLI (17 pts), and HART+PLI+chemotherapy (7 pts) were 15, 21, 26 and 55 IU/l, respectively. A mild increase of ALAT levels observed in the HART+PLI+chemotherapy sub-group was non-symptomatic. Three-year actuarial loco-regional control rate in a group of 62 patients was 94%. None of the patients who received PLI developed metastases during the follow-up, compared to 10 out of 38 patients (26%) with no PLI. A difference in metastases-free survival in favor of HART+PLI can be, however, attributed to selection of patients for PLI who were in better general health and stage of disease than those treated with HART.

CONCLUSIONS

Further use of PLI may be limited due to asymptomatic, but detectable biochemical changes of liver function when PLI is sequentially combined with chemotherapy. HART, on the other hand, provides acceptable rate of local control, and is well tolerated, also when combined with postoperative chemotherapy.

Preoperative hyper-fractionated accelerated radiotherapy (HART) in locally advanced rectal cancer (LARC) immediately followed by surgery. A prospective phase II trial

BACKGROUND AND PURPOSE

We aim to report on local control in a phase II trial on preoperative hyper-fractionated and accelerated radiotherapy schedule (HART) in locally advanced resectable rectal cancer (LARC). This fractionation schedule was designed to keep the overall treatment time (OTT) as short as possible.

PATIENTS AND METHODS

This is a prospective trial on patients with UICC stages II and III rectal cancer. The patients were submitted to a total dose of 41.6 Gy, delivered in 2.5 weeks at 1.6 Gy per fraction twice a day with a 6-h interfraction interval. Surgery was performed within 1 week after the end of irradiation. Adjuvant chemotherapy was delivered in a subset of patients.

RESULTS

Two hundred and seventy nine patients were entered and 250 are fully assessable, with a median follow-up of 39 months. The 5-years actuarial local control (LC) rate is 91.7%. The overall survival (OS) is 59.6%. The freedom from disease relapse (FDR) is 71.5%. Downstaging was observed in 38% of the tumors.

CONCLUSION

The actuarial LC at 5 years is 91.7%, although we are dealing with stages II-III LARC, mainly located in the lower rectum (median distance = 5 cm). The pattern of failure is dominated by distant metastases and treatment intensification will obviously require a systemic approach.

Histopathology of residual rectal carcinoma following preoperative radiochemotherapy

Preoperative radiotherapy with (CRT) or without chemotherapy (RT) in the management of patients with locally advanced rectal carcinoma is increasingly accepted as therapeutic modality to reduce local recurrence and improve survival, decrease tumor size and/or stage, has less toxicity compared to postoperative therapy, improves sphincter preservation and the ability to perform a curative resection. In a brief review of literature we discussed the possible prognostic role of most important pathologic parameters and their clinical implications. At present, predictive value of tumor response to neoadjuvant therapy remains uncertain, whether evaluated as five-point histological tumor regression grade (TRG) or recently proposed three-point rectal cancer regression grade (RCRG). However, most reports emphasize reduced local reccurence rates and disease-free survival advantage in patients with complete tumour regression or tumour down-staging, occuring in up to 20% and 60% of cases, respectively. Patients with advanced post-treatment tumour stage (ypT3/4), positive lymph nodes (ypN1/2), vascular invasion, positive circumferential resection margin, clearance < 2mm, or absence of tumor regression are shown to have poor clinical outcome. Among CRT-induced morphological features, only "fibrotic-type" stromal response with minimal inflammatory infiltrates and absence of surface ulceration are correlated to recurrence-free survival. Preliminary unpublished results of a pilot study from our multidisciplinary prospective trial relate to correlation of histopathologic parameters and morphologic changes to rectal cancer regression grade (RCRG). Therefore, we studied 22 consecutive patients, mean age 56 (range 23-69) years, with transmural cT3/4 stage and were subgrouped as follows: RCRG-1 (7 patients, 31.8%), RCRG-2 (9 patients, 40.,9%) and RCRG-3 (6 patients, 27,2%). In addition, 14 patients (63%) showed tumour downstaging and only 1 patient (4.5%) nodal down-staging after ypTNM restaging. There was the predominance of fibrotic-type stroma (16 patients, 72.8%) versus fibro-inflammatory response (6 patients, 27.2%), frequent tumoral necrosis (13 patients, 59%) but infrequent surface ulceration (5 patients, 22.7%) and peritumoural eosinophylic infiltration as well as endocrine cell differentiation (4 patients, 18%). The second aim of our study was to investigate determinants of radiosensitivity, i.e. the relationship between proliferative activity indices (Ki-67 and PCNA) as well as the induction of apoptosis (p53) and the tumour regression (RCRG) after neoadjuvant CRT. The interaction between Ki-67 and PCNA immunoexpression levels and the benefit of CRT was significant for Ki-67 (p = 0.03), but not for PCNA (p = 0.08) and p53 levels (p = 0.4). In a conclusion, high percentage of Ki-67-positive tumor cells in the preoperative biopsy predicts an decreased treatment response after preoperative CRT of rectal cancer. However, long-term follow-up and large studies are necessary to establish the value of regression grade and the need for its prediction by reliable biological markers.

Preoperative hyperfractionated accelerated radiotherapy (HART) and concomitant CPT-11 in locally advanced rectal carcinoma: a phase I study

PURPOSE

Patients with locally advanced rectal carcinoma are at risk for both local recurrence and distant metastases. We demonstrated the efficacy of preoperative hyperfractionated accelerated radiotherapy (HART). In this Phase I trial, we aimed at introducing chemotherapy early in the treatment course with both intrinsic antitumor activity and a radiosensitizer effect.

METHODS AND MATERIALS

Twenty-eight patients (19 males; median age 63, range 28-75) with advanced rectal carcinoma (cT3: 24; cT4: 4; cN+: 12; M1: 5) were enrolled, including 8 patients treated at the maximally tolerated dose. Escalating doses of CPT-11 (30-105 mg/m(2)/week) were given on Days 1, 8, and 15, and concomitant HART (41.6 Gy, 1.6 Gy bid x 13 days) started on Day 8. Surgery was to be performed within 1 week after the end of radiochemotherapy.

RESULTS

Twenty-six patients completed all preoperative radiochemotherapy as scheduled; all patients underwent surgery. Dose-limiting toxicity was diarrhea Grade 3 occurring at dose level 6 (105 mg/m(2)). Hematotoxicity was mild, with only 1 patient experiencing Grade 3 neutropenia. Postoperative complications (30 days) occurred in 7 patients, with an anastomotic leak rate of 22%.

CONCLUSIONS

The recommended Phase II dose of CPT-11 in this setting is 90 mg/m(2)/week. Further Phase II exploration at this dose is warranted.

Predictive factors in locally advanced rectal cancer treated with preoperative hyperfractionated and accelerated radiotherapy

This study examines the prognostic significance of pathologic factors in patients with primary locally advanced rectal cancer treated prospectively with preoperative radiotherapy. From 1992 to 1998, 104 patients with rectal cancer of grades T3 or T4 and any N underwent preoperative radiotherapy followed by surgical resection. Survival curves were estimated according to the Kaplan-Meier method. Correlation of outcome with clinicopathologic variables (pathologic tumor and lymph node staging, histology, radial resection margin [RRM], clearance, vessel involvement, and tumor regression grade [TRG], quantitated in 5 grades) was evaluated using the Cox proportional hazards model. None of the patients achieved a histologically confirmed complete pathologic response, but 79% of the patients showed partial tumor regression (TRG2-4) and 21% did not show any tumor regression (TRG5). Among the tumors, 22% were of a mucinous type. The RRM was free of tumor in 76% of the surgical specimens. The median clearance was 2 mm. Vascular invasion was present in 37 cases (36%). In the univariate analysis, lymph node metastases, absence of tumor regression, positive RRM, and vascular invasion were correlated with adverse overall survival and disease-free survival; absence of tumor regression, positive RRM, and clearance <2 mm were correlated with local recurrences; and advanced pT stage was correlated only with disease-free survival. However, in the multivariate analysis, only lymph node metastases and RRM were independent prognostic factors for overall survival and disease-free survival, and clearance <2 mm was an independent prognostic factor for local control. Pathologic parameters remain strong determinants of local recurrence and survival in locally advanced rectal cancer, treated preoperatively with hyperfractionated and accelerated radiotherapy. We show that patients with advanced pT, positive lymph nodes, vascular invasion, positive RRM, clearance <2 mm, or absence of tumor regression are known to have poor clinical outcome.

Preoperative hyperfractionated radiotherapy for locally advanced rectal cancers: a phase I-II trial

PURPOSE

To assess the toxicity, pathologic response rates, type of surgery, and oncologic results in a prospective Phase I-II trial using pure hyperfractionated radiotherapy (RT) preoperatively in locally advanced rectal cancer.

METHODS AND MATERIALS

Between September 1997 and April 2000, 50 patients with T3-T4 or N1 rectal cancers were treated preoperatively with 50 Gy (45 Gy to the pelvis and a 5-Gy tumor boost) in 40 fractions of 1.25 Gy during 4 weeks. The pretreatment tumor stage as determined by CT and endorectal ultrasonography (80% of patients) included 1 Stage T2 (2%), 45 T3 (90%), and 4 T4 (8%). Nodal involvement (N1) was documented in 26 patients (52%). Surgery was performed at a median interval of 45 days (range 26-114 days) after RT completion. Seventeen patients who presented with pT4 or pN1 and/or pM1 received 5-fluorouracil-based chemotherapy postoperatively.

RESULTS

All patients completed the RT schedule as planned. Severe acute toxicities included two Grade 3 skin reactions (4%) that did not require a break. The other acute toxicities were Grade 2 or less (skin, diarrhea, urinary, rectal tenesmus, and fatigue). A complete pathologic response was observed in 7 patients (14%), and microscopic residual cancer was found in 10 (20%). Of the 20 patients presenting with tumor located < or = 6 cm from the anal verge, sphincter-saving surgery was performed in 14 (70%). At 3 years, the actuarial locoregional control rate was 90.5%, and the disease-free survival rate was 74.6%. At a median follow-up of 32 months, 4 patients (8%) presented with severe late complications (Grade 3-4) that might have been RT related (one rectovaginal fistula, two chronic perineal fistulas, and one bilateral ureteral stenosis).

CONCLUSION

In locally advanced rectal cancer, preoperative hyperfractionated RT to a total dose of 50 Gy is feasible, with acceptable acute and late toxicity and an objective downstaging effect. In view of these results, this schedule might be used as a basis for additional investigation regarding RT dose escalation or the addition of concomitant chemotherapy.

Role of metallothioneins in irradiated human rectal carcinoma

BACKGROUND

Metallothioneins (MT) are low-molecular weight, metal-binding proteins that play a role in cellular proliferation and differentiation, as well as in cellular defense mechanisms. They act as scavengers of free radicals produced by irradiation. A number of in vitro and in vivo studies have linked overexpression of cellular MT with tumor cell resistance to radiation. This is the first study that investigates whether MT expression is involved in the radioresistance of rectal carcinoma.

METHODS

Using a mouse monoclonal antibody, MT expression was analyzed by immunohistochemistry on surgical samples (n = 85) from 85 patients with locally advanced rectal carcinoma who were treated preoperatively with a hyperfractionated and accelerated radiotherapy schedule and on tumor biopsies (n = 13) obtained before treatment. The potential correlations between MT expression and pathologic variables and survival were examined.

RESULTS

MT were expressed strongly in both the cytoplasm and nucleus of tumor cells in 7 biopsy and 42 surgical samples. A comparison of MT expression in biopsy and surgical specimens showed that MT expression did not change after irradiation in most cases. Against all expectations, MT were expressed more frequently in tumors from responders than in those from the nonresponders (P = 0.02). There was no correlation between MT expression and tumor stage, histology after radiotherapy, or survival.

CONCLUSION

These findings do not Cansupport the hypothesis that MT overexpression at the end of radiotherapy is a marker for radiation resistance.

Adjuvant therapy of resectable rectal cancer

The two conventional treatments for clinically resectable rectal cancer are surgery followed by postoperative combined modality therapy and preoperative combined modality therapy followed by surgery and postoperative chemotherapy. Preoperative therapy (most commonly combined modality therapy) has gained acceptance as a standard adjuvant therapy. The potential advantages of the preoperative approach include decreased tumor seeding, less acute toxicity, increased radiosensitivity due to more oxygenated cells, and enhanced sphincter preservation. There are a number of new chemotherapeutic agents that have been developed for the treatment of patients with colorectal cancer. Phase I/II trials examining the use of new chemotherapeutic agents in combination with pelvic radiation therapy are in progress.

Long-term prognostic significance of extent of rectal cancer response to preoperative radiation and chemotherapy

OBJECTIVE

To determine whether selected clinicopathologic factors, including the extent of pathologic response to preoperative radiation and chemotherapy (RT +/- chemo), have an impact on long-term recurrence-free survival (RFS) in patients with locally advanced primary rectal cancer after optimal multimodality therapy.

SUMMARY BACKGROUND DATA

Although complete pathologic response to preoperative RT +/- chemo has been detected in up to 30% of rectal cancers, its significance on long-term outcome has not been widely reported. Previous retrospective studies evaluating clinical outcome in patients with complete or near-complete pathologic response documented good prognosis in this population but were limited by median follow-up in the range of 2 to 3 years.

METHODS

Sixty-nine patients with locally advanced (T(3-4) and/or N1) primary rectal cancer were prospectively identified. All were treated at one institution with preoperative RT to the pelvis (at least 4,500 cGy). Forty patients received concurrent preoperative 5-fluorouracil-based chemotherapy and 27 received both pre- and postoperative chemotherapy. Patients underwent resection 4 to 7 weeks after completion of RT. TNM stage, angiolymphatic or perineural invasion, and extent of response to preoperative RT +/- chemo were determined by pathologic evaluation. Adverse pathologic features were defined as the presence of angiolymphatic and/or perineural invasion. RFS at 5 years was determined by the Kaplan-Meier method.

RESULTS

With a median follow-up of 69 months, 5-year RFS was 79%. RFS was significantly worse for patients with aggressive pathologic features and positive nodal status identified in the postirradiated surgical specimen. Risk ratios for RFS were 3.68 for the presence of aggressive pathologic features and 4.64 for node-positive rectal cancers. In patients with greater than 95% rectal cancer response to preoperative RT +/- chemo, only one patient has died as a consequence of cancer, another has died of an unrelated cause, and the remainder were free of disease with a minimum follow-up of 47 months.

CONCLUSIONS

These data suggest that a marked response to preoperative RT +/- chemo may be associated with good long-term outcome but was not predictive of RFS. The presence of poor histopathologic features and positive nodal status are the most important prognostic indicators after neoadjuvant therapy.

Importance of tumor regression assessment in predicting the outcome in patients with locally advanced rectal carcinoma who are treated with preoperative radiotherapy

BACKGROUND

Locally advanced rectal carcinoma has a poor prognosis. However, since the introduction of preoperative radiotherapy, the outcome of patients with rectal carcinoma has been reported to have improved. Nevertheless, to the authors' knowledge few data are available regarding the histopathologic response to radiotherapy as assessed on surgical specimens as a potential predictive factor for outcome.

METHODS

To estimate the effect of radiotherapy on rectal carcinoma, the authors retrospectively reviewed the surgical specimens of 102 patients with T3-4, N0 or > or = N1 rectal carcinoma and 1 patient with T2 but N1 rectal carcinoma. All patients were treated preoperatively with a hyperfractionated accelerated radiotherapy schedule in a prospective protocol (Trial 93-01). Using a standardized approach, tumor regression was graded using a system that varies from Grade 1 (tumor regression Grade [TRG] 1) when complete tumor regression is observed to Grade 5 (TRG5) when no tumor regression is observed.

RESULTS

Radiotherapy resulted in tumor downstaging in 43% of the patients. There were 2 pT1 tumors (2%), 21 pT2 tumors (20%), 66 pT3 tumors (64%), and 14 pT4 tumors (14%) after treatment. Regional lymph nodes were involved in 55 patients (53%). None of the patients demonstrated a complete tumor regression after radiotherapy, but in 79% of the specimens a partial tumor regression was observed (TRG1: 0%; TRG2: 20%; TRG3: 39%; TRG4: 20%; and TRG5: 21%). The median actuarial overall survival (OS) and disease-free survival (DFS) were 52 months. Actuarial local recurrence rates at 2 years and 5 years were 6.4% and 7.6%, respectively. Univariate analysis showed the actuarial DFS to be significantly lower in patients with lymph node metastases (P = 0.0004) and advanced pT stages (pT3-4) (P = 0.03). A favorable outcome for OS, DFS, and local control was observed in patients with TRG2-4 (i.e., responders) compared with patients with TRG5 (i.e., nonresponders), but also in patients with low residual tumor cell density (TRG2, 3, and 4). On multivariate analysis, TRG remained an independent prognostic indicator for local tumor control.

CONCLUSIONS

Tumor regression as well as residual tumor cell density were found to be predictive factors of survival in rectal carcinoma patients after preoperative radiotherapy. Even after preoperative radiotherapy, the pathologic stage of the surgical specimen remained a prognostic factor. The use of a standardized approach for pathologic evaluation must be implemented to allow comparison between the results of various treatment approaches.

Emerging standards of radiotherapy combined with radical rectal cancer surgery

For patients with resectable rectal cancer treated with total mesorectal excision, the routine use of radiotherapy should be omitted for stage I of the disease and for lesions located higher than 10 cm from the anal verge. Preoperative radiotherapy may be considered for all patients with a lesion with deep perirectal fat infiltration located in the lower two thirds of the rectum. The other option is to offer postoperative radiotherapy for patients with a positive surgical margin, N+ stage disease, mesorectal tumour implants, high tumour grade, perineural invasion, extramuscular blood and lymphatic vessel invasion and with inadvertent tumour perforation. The lower risk of small bowel damage and probable higher efficacy are arguments for the use of preoperative radiotherapy instead of postoperative radiotherapy. The impairment of anorectal function appears to be most frequent late postirradiation sequel. The analysis of acute complications (including toxic deaths) compliance, cost and convenience favours 5 x 5 Gy preoperative irradiation with immediate surgery for patients with resectable tumours in comparison to other commonly used schemes of radiotherapy. These advantages should be weighed against approximately 1.5% risk of late neurotoxicity. There is no clear answer to the question whether preoperative conventional radio(chemo)therapy offers an advantage in sphincter preservation. To answer this question, the results of two ongoing randomised trials are awaited. For patients with unresectable cancers, long-term preoperative radio(chemo)therapy with delayed surgery is a preferable scheme. The total mesorectal irradiation should be employed for mid- and low-lying lesions. Therefore, during radiotherapy planning, a contrast enema should be used to identify the anorectal ring, anatomically corresponding with the lowest edge of the mesorectum.

Healing of experimental colonic anastomoses: effects of combined preoperative high-dose radiotherapy and intraperitoneal 5-fluorouracil

To study the effects of preoperative radiochemotherapy (RCT) on the healing of colonic anastomosis, the rectosigmoid colon in male Wistar rats was irradiated up to an end dose of 41.6 Gy (RT) or sham-irradiated (SR). During the last 5 days of the irradiation schedule, 5-fluorouracil (5-FU) was administered intraperitoneally in either a high dose (20 mg/kg, chemotherapy-high dose [CH]) or a low dose (10 mg/kg, chemotherapy-low dose [CL]). Animals were randomly arranged into six groups: group I, control (SR + saline intraperitoneally); group II, RT only; group III, SR + CL; group IV, RT + CL; group V, SR + CH; group VI, RT + CH. Four days after RCT, a side-to-side anastomosis was constructed between the irradiated rectosigmoid and the nonirradiated caecum. Animals were killed 10 days postoperatively. No significant differences were found in the anastomotic bursting pressure or the bursting wall tension. In group VI, mitoses were less (P < 0.01) and mucosal ulceration was more (P = 0.03) pronounced compared to group I. Sclerotic arteries were seen in all irradiated groups and in animals that received high-dose 5-FU alone. 5-FU administration in high or low dose, with or without RT, induced more inflammation in the submucosa compared to controls (P < 0.05). Conclusively, RCT has no detrimental effect on the mechanical strength of colonic anastomosis in this rat model. However, RCT with high-dose 5-FU induces more histological alterations at the anastomotic site.

Influence of preoperative combined radiochemotherapy on surgical outcome and colonic anastomotic healing: experimental study in the rat

PURPOSE

To study the influence of combined preoperative hyperfractionated irradiation with intraperitoneal 5-fluorouracil (5-FU) on surgical outcome and colonic anastomotic healing in a rat model.

METHODS

Male Wistar rats were given 41.6 Gy of preoperative radiotherapy (RT) or sham irradiation, with intraperitoneal 5-FU at low dose (10 mg/kg) or high dose (20 mg/kg). Animals were arranged in 6 groups: RT + low-dose 5-FU (RCT-L), RT + high-dose 5-FU (RCT-H), sham RT + low-dose 5-FU (CT-L), sham RT + high-dose 5-FU (CT-H), RT alone (R), and a control group (sham RT + intraperitoneal saline). Side-to-side colonic anastomoses were constructed from one irradiated and one nonirradiated limb 4 days after radiochemotherapy. Animals were sacrificed 10 days after surgery.

RESULTS

Compared to controls, more complications occurred in group RCT-H (50% versus 0%, p = 0.01). Adhesion formation was more intense in groups RCT-H and CT-H (p < 0.001 and p = 0.001, respectively). After therapy, white blood cell counts dropped significantly in all irradiated animals (p < 0.01), and platelet counts decreased significantly in group RCT-H (p = 0.01). No significant differences were noticed in anastomotic bursting pressure when the treated groups were compared to each other or to the control group.

CONCLUSIONS

Neoadjuvant radiochemotherapy has no adverse effect on the strength of colonic anastomosis in this rat model. However, the combined RT with high-dose 5-FU does increase operative morbidity and adhesion formation.

Prospective trial of preoperative concomitant boost radiotherapy with continuous infusion 5-fluorouracil for locally advanced rectal cancer

RATIONALE

To evaluate the response to a concomitant boost given during standard chemoradiation for locally advanced rectal cancer.

METHODS AND MATERIALS

Concomitant boost radiotherapy was administered preoperatively to 45 patients with locally advanced rectal cancer in a prospective trial. Treatment consisted of 45 Gy to the pelvis with 18 mV photons at 1.8 Gy/fraction using a 3-field belly board technique with continuous infusion 5FU chemotherapy (300mg/m(2)) 5 days per week. The boost was given during the last week of therapy with a 6-hour inter-fraction interval to the tumor plus a 2-3 cm margin. The boost dose equaled 7.5 Gy/5 fractions (1.5 Gy/fraction); a total dose of 52.5 Gy/5 weeks was given to the primary tumor. Pretreatment tumor stage, determined by endorectal ultrasound and CT scan, included 29 with T3N0 [64%], 11 T3N1, 1 T3Nx, 2 T4N0, 1 T4N3, and 1 with TxN1 disease. Mean distance from the anal verge was 5 cm (range 0-13 cm). Median age was 55 years (range 33-77 years). The population consisted of 34 males and 11 females. Median time of follow-up is 8 months (range 1-24 months).

RESULTS

Sphincter preservation (SP) has been accomplished in 33 of 42 (79%) patients resected to date. Three patients did not undergo resection because of the development of metastatic disease in the interim between the completion of chemoradiation (CTX/XRT) and preoperative evaluation. The surgical procedures included proctectomy and coloanal anastomosis (n = 16), low anterior resection (n = 13), transanal resection (n = 4). Tumor down-staging was pathologically confirmed in 36 of the 42 (86%) resected patients, and 13 (31%) achieved a pathologic CR. Among the 28 tumors (67%) located <6 cm from the anal verge, SP was accomplished in 21 cases (75%). Although perioperative morbidity was higher, toxicity rates during CTX/XRT were comparable to that seen with conventional fractionation. Compared to our contemporary experience with conventional CTX/XRT (45Gy; 1.8 Gy per fraction), improvements were seen in SP (79% vs. 59%; p = 0.02), SP for tumors <6 cm from the anal verge (75% vs. 42%; p = 0.003), and down-staging (86% vs. 62%; p = 0.003).

CONCLUSION

The SP rate with concomitant boost radiation has been highly favorable with rates of response which are higher than those previously reported for chemoradiation without administration of a boost. Further evaluation of this radiotherapeutic strategy appears warranted.

Role of adjuvant therapy in adenocarcinoma of the rectum

Combined modality therapy is the standard adjuvant therapy for selected patients with adenocarcinoma of the rectum. In the postoperative setting, the primary goal is to decrease local recurrence and improve overall survival. In the preoperative setting, adjuvant therapy has the additional potential benefit of enhancing sphincter preservation and less acute toxicity as compared with postoperative adjuvant therapy. Investigational trials are in progress to examine new systemic chemotherapeutic agents and altered radiation fractionation schemes.

Preoperative radiation therapy for patients with T2-T3 carcinoma of the middle-to-lower rectum

BACKGROUND

The aim of this study was to determine the effects of preoperative radiation therapy (RT) on the objective responses of patients with rectal carcinoma to their treatment. These effects were assessed with endorectal ultrasound (EUS) evaluation, histopathologic grading of postirradiation tumor mass reduction in the surgical specimen, and analysis of local and distant recurrences.

METHODS

Fifty-nine consecutive patients with palpable adenocarcinoma of the rectum, classified by EUS examination as uT2-uT3 (which meant involvement of the muscular layer and the perirectal adipose tissue, respectively), received 45 grays (Gy) over 3 weeks (2 fractions per day of 1.5 Gy each) given as photons supplied through a high-energy linear accelerator (18 MeV) through 3 fields: 1 posterior and 2 opposed lateral. Surgery was scheduled 2-3 weeks after the end of RT and included a sphincter-saving resection (39 patients) and an abdominoperineal resection (20 patients).

RESULTS

Greatest tumor dimension, which was evaluated with rectal endoscopy before RT and measurement of the lesion in the fresh specimen, showed a decrease among two-thirds of the patients; the decrease amounted to approximately one-third of the initial measurement. An echoendoscopic downstaging of the T component was observed among 24.5% of the patients. Complete tumor regression occurred in 8.5% of patients, whereas in 69% only the presence of rare residual cancer cells and prominent fibrosis were found at the pathologic examination of the specimen. Finally, the tumor regressed to pT0 and pT1 in 13.6% of the patients. The overall and disease free 2-year survival rates were 94.0% and 73.7%, respectively, for pT2 and pT3 patients, and 100% for those whose tumors regressed to pT0-pT1 after a median follow-up of 2 years.

CONCLUSIONS

Hyperfractionated preoperative RT appears to be efficient in achieving tumor shrinkage and destroying the tumor. In this study, the subset of patients with a good response to RT therapy had an excellent clinical outcome at the time of a 2-year follow-up.

Tumor downstaging and sphincter preservation with preoperative chemoradiation in locally advanced rectal cancer: the M. D. Anderson Cancer Center experience

PURPOSE

To evaluate the rates of tumor downstaging after preoperative chemoradiation for locally advanced rectal cancer.

MATERIALS AND METHODS

Preoperative chemoradiotherapy (CTX/XRT) that delivered 45 Gy in 25 fractions over 5 weeks with continuous infusion 5-fluorouracil (300 mg/m2/day) was given to 117 patients. The pretreatment stage distribution, as determined by endorectal ultrasound (u), included uT2N0 in 2%, uT3N0 in 47%, uT3N1 in 49%, and uT4N0 in 2% of cases; endorectal ultrasound was not performed in 13% of cases (15 patients). Approximately 6 weeks after completion of CTX/XRT, surgery was performed.

RESULTS

The pathological tumor stages were Tis-2N0 in 26%, T2N1 in 5%, T3N0 in 21%, T3N1 in 15%, T4N0 in 5%, and T4NI in 1%; a complete response (CR) to preoperative CTX/XRT was pathologically confirmed in 32 (27%) of patients. Tumor downstaging occurred in 72 (62%) cases. Only 3% of cases had pathologic evidence of progressive disease. Pretreatment tumor size (< 5 cm vs. > or = 5 cm) was the only factor predictive of tumor downstaging (p < 0.04). A decrease of > 1 T-stage level was accomplished in 45% of those downstaged. Overall, a sphincter-saving (SP) procedure was possible in 59% of patients and an abdominoperineal resection (APR) was required in 41 % of cases. Factors predictive of SP included downstaging (p < 0.03), age > 40 years (p < 0.007), pretreatment tumor distance, 3 to 6 cm from the anal verge (p < 0.00001), tumor size <6 cm (p < 0.02), mobility (p < 0.004), tumor stage <T4 (p < 0.01), and uN negative (p < 0.008). SP was performed in 23 patients (72%) with a CR and in 48 (67%) of downstaged cases. Among the 69 tumors located < 6 cm from the anal verge, 29 (42%) were resected with a SP. The level of response was important for tumors located < 6 cm from the anal verge because a SP was performed in 9 of the 17 (53%) CRs in this group while only 20 of 52 patients (38%) had a SP when residual disease was present after CTX/XRT. For tumors located > 6 cm from the anal verge, SP was performed in 14 of the 15 (93%) patients with a CR and 32 of 33 (97%) of patients with residual disease (p < 0.00004).

CONCLUSIONS

Significant tumor downstaging results from preoperative chemoradiation allowing sphincter sparing surgery in over 40% of patients whose tumors were located < 6 cm from the anal verge and who otherwise would have required colostomy.

Superior sulcus lung tumors: impact of local control on survival

OBJECTIVES

Our goal was to assess patient survival and response to treatment for superior sulcus tumors treated with combined radiation therapy and surgery when possible, or with radiation alone when surgery was not possible.

METHODS

Seventy-three patients were treated for primary non-small cell carcinoma of the superior pulmonary sulcus. Thirty-four patients received combined resection and irradiation. Thirty-nine patients who had extensive primary disease, distant metastases, or who were medically unfit for surgery were treated with radiation alone. Thirty-one patients (91%) assigned to the resection/irradiation group completed treatment. Combined therapy patients routinely received 40 Gy before the operation, with additional postoperative irradiation based on the surgical findings.

RESULTS

Overall survival at 5 years was 19% and disease-specific survival was 20% for all patients. Overall survival and disease-specific survival at 5 years for the resection/irradiation group were 33% and 38%, respectively. Significant indicators of poor prognosis included unresected primary disease, low performance score, T4 stage, or positive node status. Eighty-two percent of the patients who received irradiation alone were treated with palliative intent. Freedom from local-regional progression, achieved initially in 66% of these patients, was associated with a median survival of 8 months. Median survival for 7 patients considered for definitive irradiation was 25 months. During the first 18 months, distant failures occurred in approximately 35% of patients in each treatment group.

CONCLUSIONS

Selection of medically fit patients with resectable disease for combined surgery and aggressive radiation therapy resulted in a high likelihood of local control. Overall survival for the resection/irradiation group was significantly poorer for patients with T4 stage, nodal disease, or Horner's syndrome. Distant metastases eventually developed in 56% of patients undergoing resection. Median survival in the resection/irradiation group was significantly prolonged for those patients who could tolerate high-dose radiation treatment.

High-dose preoperative radiotherapy does not alter the strength of unilaterally irradiated colon anastomoses in rats

PURPOSE

We studied the influence of preoperative radiotherapy on the strength of colon anastomoses in rats. We compared a conventional (2 Gy/fraction; 1 fraction/day; 5 days/week; cumulative doses of 40.0, 60.0, and 80.0 Gy) and a hyperfractionated schedule (1.6 Gy/fraction, 2 fractions/day, 5 days/week, cumulative doses of 41.6, 60.8, and 80.0 Gy). We compared unilaterally with bilaterally irradiated anastomoses for two conventional radiation schedules.

METHODS AND MATERIALS

The rectosigmoid was always irradiated. Depending on the experiment, the cecum was irradiated or not. A side-to-side anastomosis between rectosigmoid and cecum was constructed the day following the last irradiation. The strength of the anastomosis was evaluated by means of a bursting pressure (BP) measurement after 10 days. A control group and a sham-treated group were carried out.

RESULTS

Compared to controls, the strength of unilaterally irradiated anastomoses was not altered and BP values were independent of the radiation schedule and of the cumulative dose. In case of bilaterally irradiated colon anastomoses, anastomotic strength was significantly reduced at 80 Gy, but not at 40 Gy.

CONCLUSIONS

After high doses of preoperative radiotherapy, colon anastomoses in rats can be safely constructed if only one anastomotic segment is irradiated. The strength of bilaterally irradiated colon anastomoses is dose-dependent.

Phase I dose escalating trial of hyperfractionated pre-operative chemoradiation for locally advanced rectal cancer

PURPOSE

To determine the acute toxicity, post-operative complications, pathologic response and extent of downstaging to high dose pre-operative radiation using a hyperfractionated radiation boost and concurrent chemotherapy in a prospective Phase I trial.

MATERIALS & METHODS

To be eligible for this study, patients had to have adenocarcinoma of the rectum less than 12 cm from the anal verge with either Stage T4 or T3 but greater than 4 cm or greater than 40% of the bowel circumference. All patients received 45 Gy pelvic radiation (1.8 Gy per fraction). Subsequent radiation was given to the region of the gross tumor with a 2 cm margin. This "boost" treatment was given at 1.2 Gy twice daily to a total dose of 54.6 Gy for Level I, 57 Gy for Level II, and 61.8 Gy for Level III. 5-FU was given at 1g/m2 over 24 hours for a four day infusion during the first and sixth weeks of radiation, with the second course concurrent with the hyperfractionated radiation. Surgical resection was carried out 4-6 weeks following completion of chemoradiation (in curative cases) and additional adjuvant chemotherapy consisting of 5-FU and Leucovorin was given for an additional 4 monthly cycles Days 1 through 5 beginning four weeks post surgery.

RESULTS

Twenty-seven patients, age 40-82 (median 61), completed the initial course of chemoradiation and are included in the analysis of toxicity. The median follow-up is 27 months (range 8-68). Eleven patients were treated to a dose of 54.6 Gy, nine patients to 57 Gy, and seven patients to 61.8 Gy. Twenty-one patients had T3 tumors, and six patients T4 tumors. Grade III acute toxicity from chemoradiation included proctitis (5 patients), dermatitis (9), diarrhea (five), leukopenia (1), cardiac (1). Grade IV toxicities included one patient with diarrhea (on dose Level I) and one patient (on dose Level III) with cardiac toxicity (unrelated to radiation). Surgical resection consisted of abdominal perineal resection in 16 and low anterior resection in 7. Four patients did not undergo a curative resection; three initially presented with metastases and one developed metastasis during the pre-operative regimen. Post-operative complications included pelvic or perineal abscess in two (on dose Levels I & II), and delayed wound healing in two (one of whom, on dose Level III, developed perineal wound dehiscence requiring surgical reconstruction). Of the 23 patients who had a curative resection, four manifested pathologic complete responses (17.4%). Thirteen of 23 patients (57%) had evidence of pathologic downstaging and only 1/23 patients (on dose Level I) had a positive resection margin. Of these 23 patients (with a minimum follow-up of 8 months), the patient with positive margins was the only one who developed a local failure (Fisher's Exact p=.04). The 3-year actuarial OS, DFS and LC rates are 82%, 72% and 96%, respectively. Twelve of 13 patients (92% at 3 years) > or = 61 years vs. 5/10 patients (45% at 3 years) < 61 years remained disease-free (log-rank p=0.017).

CONCLUSION

This regimen of high dose pre-operative chemoradiation employing a hyperfractionated radiation boost is feasible and tolerable and results in significant downstaging in locally advanced rectal cancer. The vast majority of patients (96%) achieved negative margins, which appears to be a prerequisite for local control (p= 0.04). Older age (> or =61 years) was a significant predictor for improved DFS. This regimen (at dose Level III, 61.8 Gy) is currently being tested in a Phase II setting.

The role of radiotherapy in the surgical management of gastrointestinal cancer

Surgery is the main mode of treatment in most gastrointestinal malignancies. Radiotherapy with or without chemotherapy is playing an increasing role as an adjunct to improve local control, survival and palliation. The principles of radiotherapy and the rationale for combination therapy are presented. The current role of radiation therapy in the GI tract is discussed by various sites. New and investigational radiotherapy techniques are outlined.

[Effect radiotherapy on postoperative staging and residual tumor cell density in rectal cancers]

PURPOSE

To determine predictive factors and prognostic value of tumor downstaging and sterilization after preoperative radiotherapy for rectal cancer.

PATIENTS AND METHODS

Between 1977 and 1994, 167 patients with a histologically proven adenocarcinoma underwent preoperative radiotherapy (median dose, 44 Gy; mean time before surgery, 5 weeks). Pathologic specimens were reviewed by the same pathologist in order to specify the modified Astler Coller classification (MAC) and to quantify residual tumor cell density (RTCD).

RESULTS

According to the MAC, there were nine stage 0 (5%), 10 stage A (6%), 103 stage B1-B3 (62%) and 45 stage C1-C3 (27%) tumors. Seventeen per cent and 56% of the patients who received a dose > or = 44 Gy presented with stage 0-A and stage B1-B3 tumors, respectively, compared to 4 and 69% of those who received a dose < 44 Gy (P = 0.04). Tumor differentiation and a longer interval before surgery were significantly associated with more frequent downstaging. According to the RTCD, 62 tumors (37%) showed no or only rare foci of residual tumor cells; 62 (37%) showed an intermediate RTCD and 43 (26%) a high RTCD. No predictive factor of RTCD was statistically significant. Only post-operative staging was a significant prognostic factor (P < 0.01).

CONCLUSION

The favourable influence of higher doses of preoperative radiotherapy on pathologic stage has been observed. Tumor differentiation and time before surgery were the other significant predictive factors of tumor downstaging. Even after preoperative radiotherapy, post-operative staging retained its prognostic value.

The role of adjuvant radiation therapy in the treatment of colorectal cancer

Radiation therapy in conjunction with 5-FU chemotherapy is an effective method in the adjuvant treatment of both colon and rectal cancer.

Preoperative radiotherapy (RT) for rectal cancer: predictive factors of tumor downstaging and residual tumor cell density (RTCD): prognostic implications

PURPOSE

To determine predictive factors and prognostic value of tumor downstaging and tumor sterilization after preoperative RT for rectal cancer.

METHODS AND MATERIALS

Between 1977 and 1994, 167 patients with a histologically proven adenocarcinoma (70 T2, 65 T3, 29 T4, and 3 local recurrences) underwent preoperative RT. Median dose was 44 Gy (5-73 Gy). Surgery was performed in a mean time of 5 weeks after RT. Pathologic specimens have been reviewed by the same pathologist in order to specify the modified Astler Coller classification (MAC), and to quantify the residual tumor cell density (RTCD).

RESULTS

According to the MAC, there was 9 stage 0 (5%), 10 stage A (6%), 103 stage B1-B3 (62%), and 45 stage C1-C3 (27%) tumors. Seventeen percent and 56% of the patients who received a dose > or = 44 Gy had respectively a 0-A and a B tumor, compared to 4 and 69% in those who received a dose < 44 Gy (p = 0.04). Tumor differentiation and a longer interval before surgery were significantly associated with a more frequent downstaging, and preoperative staging correlated well to the postoperative pathological findings. According to the RTCD, 62 tumors (37%) showed no or only rare foci of residual tumor cells (Group 1); 62 (37%) showed an intermediate RTCD (Group 2); and 43 (26%) a high RTCD (Group 3). No predictive factor of RTCD was statistically significant. In univariate analysis, postoperative staging was a significant prognostic factor, with corresponding 5-year overall survival rates in 0-A, B, and C stages of 92, 67, and 26% (p < 0.01). RTCD was not a prognostic factor. However, overall and disease-free survival rates for patients with complete pathologic response of 83% at 2 and 5 years suggested a better outcome in this subgroup of patients.

CONCLUSION

The favorable influence of higher doses of preoperative RT on pathologic stage has been observed. Tumor differentiation, preoperative classification and time before surgery were the other predictive factors of tumor downstaging. However, there was no predictive factor of complete pathologic response. Even after preoperative RT, postoperative staging remained a prognostic factor.