Ellen Kapiteijn

Macroscopic Evaluation of Rectal Cancer Resection Specimen: Clinical Significance of the Pathologist in Quality Control

PURPOSE Quality assessment and assurance are important issues in modern health care. For the evaluation of surgical procedures, there are indirect parameters such as complication, recurrence, and survival rates. These parameters are of limited value for the individual surgeon, and there is an obvious need for direct parameters. We have evaluated criteria by which pathologists can judge the quality or completeness of the resection specimen in a randomized trial for rectal cancer. PATIENTS AND METHODS The pathology reports of all patients entered onto a Dutch multicenter randomized trial were reviewed. All participating pathologists had been instructed by workshops and videos in order to obtain standardized pathology work-up. A three-tiered classification was applied to assess completeness of the total mesorectal excision (TME). Prognostic value of this classification was tested using log-rank analysis of Kaplan-Meier survival curves using the data of all patients who did not receive any adjuvant treatment. RESULTS Included were 180 patients. In 24% (n = 43), the mesorectum was incomplete. Patients in this group had an increased risk for local and distant recurrence, 36.1% v. 20.3% recurrence in the group with a complete mesorectum (P =.02). Follow-up is too short to observe an effect on survival rates. CONCLUSION A patients prognosis is predicted by applying a classification of macroscopic completeness on a rectal resection specimen. We conclude that pathologists are able to judge the quality of TME for rectal cancer. With this direct interdisciplinary assessment instrument, we establish a new role of the pathologist in quality control.

Acute Side Effects and Complications After Short-Term Preoperative Radiotherapy Combined With Total Mesorectal Excision in Primary Rectal Cancer: Report of a Multicenter Randomized Trial

PURPOSE Total mesorectal excision (TME) surgery in the treatment of rectal cancer has been shown to result in a reduction in the number of local recurrences in retrospective studies. Reports on improved local control after preoperative, hypofractionated radiotherapy (RT) have led to the introduction of a prospective randomized multicenter trial, in which the effect of TME surgery with or without preoperative RT were evaluated. Any benefit in regard to a reduced local recurrence rate and possible improved survival must be weighed against potential adverse effects in both the short-term and the long-term. The present study was undertaken to assess the acute side effects of short-term, preoperative RT in rectal cancer patients and to study the influence of five doses of 5 Gy on surgical parameters, postoperative morbidity and mortality in patients randomized in the Dutch TME trial. PATIENTS AND METHODS We analyzed 1,530 Dutch patients entered onto a prospective randomized trial, comparing preoperative RT with five doses of 5 Gy followed by TME surgery with TME surgery alone, of which 1,414 patients were assessable. Toxicity from RT, surgery characteristics, and postoperative complications and mortality were compared. RESULTS Toxicity during RT hardly occurred. Irradiated patients had 100 mL more blood loss during the operation (P <.001) and showed more perineal complications (P =.008) in cases of abdominoperineal resection. The total number of complications was slightly increased in the irradiated group (P =.008). No difference was observed in postoperative mortality (4.0% v 3.3%) or in the number of reinterventions. CONCLUSION Preoperative hypofractionated RT is a safe procedure in patients treated with TME surgery, despite a slight increase in complications when compared with TME surgery only.

Radiotherapy does not compensate for positive resection margins in rectal cancer patients: report of a multicenter randomized trial

PURPOSE Circumferential resection margin (CRM) involvement is a prognostic factor for local recurrence in rectal cancer. In a randomized trial comparing preoperative radiotherapy (5 x 5 Gy), followed by total mesorectal excision (TME) with TME alone, we demonstrated the beneficial effect of short-term preoperative radiotherapy on local recurrences. Here we evaluate the effect of radiotherapy on local recurrence rates in patients with different CRM involvements. METHODS AND MATERIALS Circumferential margins were defined as positive (< or =1 mm), narrow (1.1-2 mm), or wide (>2 mm). Postoperative radiotherapy was mandatory for surgery-only patients with a positive CRM, but was not always administered and enabled us to compare local recurrence rates for patients with or without postoperative radiotherapy. Furthermore, the effect of preoperative radiotherapy was assessed in the different margin groups. RESULTS Of 120 patients in the surgery-only group with a positive CRM, 47% received postoperative radiotherapy. There was no difference in the local recurrence rate between the irradiated and nonirradiated patients (17.3% vs. 15.7%, p = 0.98). Preoperative radiotherapy was effective in patients with a narrow CRM (0% vs. 14.9%, p = 0.02) or wide CRM (0.9 vs. 5.8%, p < 0.0001), but not in patients with positive margins (9.3% vs. 16.4%, p = 0.08). CONCLUSION Preoperative hypofractionated radiotherapy has a beneficial effect in patients with wide or narrow resection margins, but cannot compensate for microscopically irradical resections resulting in positive margins.

Total mesorectal excision (TME) with or without preoperative radiotherapy in the treatment of primary rectal cancer: Prospective randomised trial with standard operative and histopathological techniques

OBJECTIVE To document local recurrence in primary rectal cancer when standardised techniques of surgery, radiotherapy, and pathology are used, and to investigate whether the local recurrence rate after total mesorectal excision permits the omission of adjuvant short term preoperative radiotherapy. DESIGN Prospective randomised study. SETTING Dutch (n = 80), English (n = 1), German (n = 1), Swedish (n = 9), and Swiss (n = 1) hospitals. SUBJECTS The first 500 randomised Dutch patients with primary rectal cancer. MAIN OUTCOME MEASURES Local recurrence, survival, operation-related factors, specific pathological tumour characteristics, short and long term morbidity, and quality of life. RESULTS Between January 1996 and April 1998, 871 Dutch and 94 other patients were randomised. Our feasibility analysis shows that cooperation between and within the participating disciplines goes well. With regard to the surgical part, this can be confirmed by the large number of operations attended by consultant surgeons (58%). The number of abdominoperineal resections appeared to be low (30%), as did the percentage of lateral margins involved (13%). The rate of adverse effects of radiotherapy was acceptable. Apart from a larger operative blood loss and a higher infective complication rate in the irradiated group, no significant differences were found with regard to morbidity and mortality between the randomised groups. CONCLUSIONS The accrual of our trial is going well and it is feasible; short term preoperative radiotherapy is safe even in combination with TME.

Beneficial effects of sorafenib on tumor progression, but not on radioiodine uptake, in patients with differentiated thyroid carcinoma.

OBJECTIVE Treatment options for patients with radioactive iodine (RaI) refractory metastases of differentiated thyroid carcinoma (DTC) are limited. We studied the effects of the multitarget tyrosine kinase inhibitor sorafenib on the reinduction of RaI uptake and tumor progression. DESIGN Open, single center, single arm 26-week prospective phase II study with open-ended extension. METHODS We treated 31 patients with progressive metastatic or locally advanced RaI refractory DTC with sorafenib 400 mg b.i.d. The primary endpoint was reinduction of RaI uptake at 26 weeks. Additional endpoints were the radiological response and the influence of bone metastases. RESULTS At 26 weeks of sorafenib therapy, no reinduction of RaI uptake at metastatic sites was observed, but 19 patients (59%) had a clinical beneficial response, eight of whom had a partial response (25%) and 11 had stable disease (34%). Seven patients had progressive disease (22%). Sorafenib was significantly less effective in patients with bone metastases. The estimated median progression free survival was 58 weeks (95% confidence interval, CI, 47-68). In general, thyroglobulin (Tg) response (both unstimulated and TSH stimulated) reflected radiological responses. The median time of the nadir of Tg levels was 3 months. Responses were not influenced by histological subtype, mutational status or other variables. No unusual side effects were observed. CONCLUSIONS Sorafenib has a beneficial effect on tumor progression in patients with metastatic DTC, but was less effective in patients with bone metastases. Diagnostic whole body scintigraphy did not reveal an effect of sorafenib on the reinduction of RaI uptake.

Anti–CTLA-4 therapy broadens the melanoma-reactive CD8+ T cell response

Anti–CTLA-4 treatment increases the diversity of the melanoma-specific CD8 T cell response. Anti–CTLA-4 Therapy Expands T Cell Range An antibody to the immune inhibitory molecule CTLA-4, ipilimumab, can improve survival in patients with advanced melanoma. However, how anti–CTLA-4 works to improve the tumor immune response in humans remains unclear. Now, Kvistborg et al. show that although the magnitude of T cell responses was largely unaltered after therapy, the number of different T cell responses was significantly increased. Indeed, this increased breadth suggests that anti–CTLA-4 may work by increasing priming of T cells to tumor-related antigens rather than boosting preexisting immune responses. If so, other strategies that improve the range of T cells may have similar success battling cancer. Anti–CTLA-4 treatment improves the survival of patients with advanced-stage melanoma. However, although the anti–CTLA-4 antibody ipilimumab is now an approved treatment for patients with metastatic disease, it remains unknown by which mechanism it boosts tumor-specific T cell activity. In particular, it is unclear whether treatment amplifies previously induced T cell responses or whether it induces new tumor-specific T cell reactivities. Using a combination ultraviolet (UV)–induced peptide exchange and peptide–major histocompatibility complex (pMHC) combinatorial coding, we monitored immune reactivity against a panel of 145 melanoma-associated epitopes in a cohort of patients receiving anti–CTLA-4 treatment. Comparison of pre- and posttreatment T cell reactivities in peripheral blood mononuclear cell samples of 40 melanoma patients demonstrated that anti–CTLA-4 treatment induces a significant increase in the number of detectable melanoma-specific CD8 T cell responses (P = 0.0009). In striking contrast, the magnitude of both virus-specific and melanoma-specific T cell responses that were already detected before start of therapy remained unaltered by treatment (P = 0.74). The observation that anti–CTLA-4 treatment induces a significant number of newly detected T cell responses—but only infrequently boosts preexisting immune responses—provides strong evidence for anti–CTLA-4 therapy–enhanced T cell priming as a component of the clinical mode of action.

Mechanisms of oncogenesis in colon versus rectal cancer.

Observations support the theory that development of left‐ and right‐sided colorectal cancers may involve different mechanisms. This study investigated different genes involved in oncogenesis of colon and rectal cancers and analysed their prognostic value. The study group comprised 35 colon and 42 rectal cancers. Rectal cancer patients had been treated with standardized surgery performed by an experienced rectal cancer surgeon. Mutation analysis was performed for p53 in eight colon cancers and for APC and p53 in 22 rectal cancers. MLH1, MSH2, Bcl‐2, p53, E‐cadherin and β‐catenin were investigated by immunohistochemistry in all colorectal tumours. APC mutation analysis of the MCR showed truncating mutations in 18 of 22 rectal tumours (82%), but the presence of an APC mutation was not related to nuclear β‐catenin expression (p=0.75). Rectal cancers showed significantly more nuclear β‐catenin than colon cancers (65% versus 40%, p=0.04). p53 mutation analysis corresponded well with p53 immunohistochemistry (p<0.001). Rectal cancers showed significantly more immunohistochemical expression of p53 than colon cancers (64% versus 29%, p=0.003). In rectal cancers, a significant correlation was found between positive p53 expression and worse disease‐free survival (p=0.008), but not in colon cancers. Cox regression showed that p53‐expression (p=0.03) was an independent predictor for disease‐free survival in rectal cancers. This study concluded that rectal cancer may involve more nuclear β‐catenin in the APC/β‐catenin pathway than colon cancer and/or nuclear β‐catenin may have another role in rectal cancer independently of APC. The p53‐pathway seems to be more important in rectal cancer, in which it also has independent prognostic value. When prognostic markers are investigated in larger series, differences in biological behaviour between colon and rectal cancer should be considered. Copyright

Total mesorectal excision (TME) with or without preoperative radiotherapy in the treatment of primary rectal cancer. Prostpective randomsied trial with standard operative and histopathological techniques. Dutch Colorectal Cancer Group.

OBJECTIVE To document local recurrence in primary rectal cancer when standardised techniques of surgery, radiotherapy, and pathology are used, and to investigate whether the local recurrence rate after total mesorectal excision permits the omission of adjuvant short term preoperative radiotherapy. DESIGN Prospective randomised study. SETTING Dutch (n = 80), English (n = 1), German (n = 1), Swedish (n = 9), and Swiss (n = 1) hospitals. SUBJECTS The first 500 randomised Dutch patients with primary rectal cancer. MAIN OUTCOME MEASURES Local recurrence, survival, operation-related factors, specific pathological tumour characteristics, short and long term morbidity, and quality of life. RESULTS Between January 1996 and April 1998, 871 Dutch and 94 other patients were randomised. Our feasibility analysis shows that cooperation between and within the participating disciplines goes well. With regard to the surgical part, this can be confirmed by the large number of operations attended by consultant surgeons (58%). The number of abdominoperineal resections appeared to be low (30%), as did the percentage of lateral margins involved (13%). The rate of adverse effects of radiotherapy was acceptable. Apart from a larger operative blood loss and a higher infective complication rate in the irradiated group, no significant differences were found with regard to morbidity and mortality between the randomised groups. CONCLUSIONS The accrual of our trial is going well and it is feasible; short term preoperative radiotherapy is safe even in combination with TME.

Neoantigen landscape dynamics during human melanoma–T cell interactions

Recognition of neoantigens that are formed as a consequence of DNA damage is likely to form a major driving force behind the clinical activity of cancer immunotherapies such as T-cell checkpoint blockade and adoptive T-cell therapy. Therefore, strategies to selectively enhance T-cell reactivity against genetically defined neoantigens are currently under development. In mouse models, T-cell pressure can sculpt the antigenicity of tumours, resulting in the emergence of tumours that lack defined mutant antigens. However, whether the T-cell-recognized neoantigen repertoire in human cancers is constant over time is unclear. Here we analyse the stability of neoantigen-specific T-cell responses and the antigens they recognize in two patients with stage IV melanoma treated by adoptive T-cell transfer. The T-cell-recognized neoantigens can be selectively lost from the tumour cell population, either by overall reduced expression of the genes or loss of the mutant alleles. Notably, loss of expression of T-cell-recognized neoantigens was accompanied by development of neoantigen-specific T-cell reactivity in tumour-infiltrating lymphocytes. These data demonstrate the dynamic interactions between cancer cells and T cells, which suggest that T cells mediate neoantigen immunoediting, and indicate that the therapeutic induction of broad neoantigen-specific T-cell responses should be used to avoid tumour resistance.

Short-course radiotherapy followed by neo-adjuvant chemotherapy in locally advanced rectal cancer – the RAPIDO trial

BackgroundCurrent standard for most of the locally advanced rectal cancers is preoperative chemoradiotherapy, and, variably per institution, postoperative adjuvant chemotherapy. Short-course preoperative radiation with delayed surgery has been shown to induce tumour down-staging in both randomized and observational studies. The concept of neo-adjuvant chemotherapy has been proven successful in gastric cancer, hepatic metastases from colorectal cancer and is currently tested in primary colon cancer.Methods and designPatients with rectal cancer with high risk features for local or systemic failure on magnetic resonance imaging are randomized to either a standard arm or an experimental arm. The standard arm consists of chemoradiation (1.8 Gy x 25 or 2 Gy x 25 with capecitabine) preoperatively, followed by selective postoperative adjuvant chemotherapy. Postoperative chemotherapy is optional and may be omitted by participating institutions. The experimental arm includes short-course radiotherapy (5 Gy x 5) followed by full-dose chemotherapy (capecitabine and oxaliplatin) in 6 cycles before surgery. In the experimental arm, no postoperative chemotherapy is prescribed. Surgery is performed according to TME principles in both study arms. The hypothesis is that short-course radiotherapy with neo-adjuvant chemotherapy increases disease-free and overall survival without compromising local control. Primary end-point is disease-free survival at 3 years. Secondary endpoints include overall survival, local control, toxicity profile, and treatment completion rate, rate of pathological complete response and microscopically radical resection, and quality of life.DiscussionFollowing the advances in rectal cancer management, increased focus on survival rather than only on local control is now justified. In an experimental arm, short-course radiotherapy is combined with full-dose chemotherapy preoperatively, an alternative that offers advantages compared to concomitant chemoradiotherapy with or without postoperative chemotherapy. In a multi-centre setting this regimen is compared to current standard with the aim of improving survival for patients with locally advanced rectal cancer.Trial registrationClinicalTrials.gov NCT01558921