Rectal cancer : when is the local recurrence risk low enough to refrain from the aim to prevent it?

Recently, preliminary results of the OCUM study (optimized surgery and MRI-based multimodal therapy of rectal cancer) were published and raised concern in the scientific community. In this observational study, the circumferential resection margin status assessed in preoperative MRI (mrCRM) was used to decide for either total mesorectal excision (TME) alone or neoadjuvant radiochemotherapy (nRCT). In contrast to current guidelines, neither T3 stage (with negative CRM) nor clinically positive lymph nodes were an indication for nRCT. Pathologically node-positive patients received chemotherapy (ChT). Overall, 230 patients were included, of whom 96 CRM-positive patients received nRCT. The CRM was accurately predicted in MRI, the rate of mesorectal plane resection was high. Recurrence rates have not yet been reported, but an impressive rate of down-staging for both T and N stage after nRCT was observed, while acute side effects were minimal. Nonetheless, the authors conclude that a substantial number of patients could be "spared severe radiation toxicity" and propagate their concept for prospectively replacing current guidelines. This is based on the hypothesis that CRM is a valid surrogate parameter for the risk of local recurrence and in case of a negative CRM, nRCT becomes dispensable. Moreover, it is assumed that lymph node status is no more relevant. Both assumptions are a contradiction to recent data from randomized studies as specified below. As 5-year locoregional recurrence rate (LRR) of only of 5-8% and < 5% in low risk rectal cancer can be achieved by the addition of RT, the noninferiority of surgery alone can not be presumed unless the expected 5-year LRR is ≤ 5-8%, whereas any excess of this range renders the study design inacceptable. Unless a publication explicitly specifies 5-year LRR, results are not exploitable for clinical decisions.

Long-term outcome after neoadjuvant radiochemotherapy in locally advanced noninflammatory breast cancer and predictive factors for a pathologic complete remission : results of a multivariate analysis

BACKGROUND

An earlier published series of neoadjuvant radiochemotherapy (NRT-CHX) in locally advanced noninflammatory breast cancer (LABC) has now been updated with a follow-up of more than 15 years. Long-term outcome data and predictive factors for pathologic complete response (pCR) were analyzed.

PATIENTS AND METHODS

During 1991-1998, 315 LABC patients (cT1-cT4/cN0-N1) were treated with NRT-CHX. Preoperative radiotherapy (RT) consisted of external beam radiation therapy (EBRT) of 50 Gy (5 × 2 Gy/week) to the breast and the supra-/infraclavicular lymph nodes combined with an electron boost in 214 cases afterwards or-in case of breast conservation-a 10-Gy interstitial boost with (192)Ir afterloading before EBRT. Chemotherapy was administered prior to RT in 192 patients, and concomitantly in 113; 10 patients received no chemotherapy. The update of all follow-up ended in November 2011. Age, tumor grade, nodal status, hormone receptor status, simultaneous vs. sequential CHX, and the time interval between end of RT and surgery were examined in multivariate terms with pCR and overall survival as end point.

RESULTS

The total pCR rate after neoadjuvant RT-CHX reached 29.2%, with LABC breast conservation becoming possible in 50.8% of cases. In initially node-positive cases (cN+), a complete nodal response (pN0) after NRT-CHX was observed in 56% (89/159). The multivariate analysis revealed that a longer time interval to surgery increased the probability for a pCR (HR 1.17 [95% CI 1.05-1.31], p < 0.01). However, in large tumors (T3-T4) a significantly reduced pCR rate (HR 0.89 [95% CI 0.80-0.99], p = 0.03) was obtained. Importantly, pCR was the strongest prognostic factor for long-term survival (HR 0.28 [95% CI 0.19-0.56], p < 0.001).

CONCLUSION

pCR identifies patients with a significantly better prognosis for long-term survival. However, a long time interval to surgery (> 2 months) increases the probability of pCR after NRT-CHX.

Preoperative chemoradiotherapy and postoperative chemotherapy with 5-fluorouracil and oxaliplatin versus 5-fluorouracil alone in locally advanced rectal cancer: First results of the German CAO/ARO/AIO-04 randomized phase III trial

LBA3505

Background: The German CAO/ARO/AIO-94 trial established preoperative chemoradiotherapy (CRT), surgery, and postoperative chemotherapy with 5-FU as standard treatment for locally advanced rectal cancer. With this approach local relapse rates are below 10%. The development of distant metastasis is the predominant mode of failure. Integrating more effective systemic treatment into combined modality therapy was the goal of CAO/ARO/AIO-04. Methods: Between 7/2006-2/2010, patients with rectal cancer within 12 cm from the anal verge and clinical evidence of perirectal fat or lymph node involvement were randomly assigned to receive preoperative CRT, surgery, and adjuvant chemotherapy with 5-FU according to CAO/ARO/AIO-94 (arm 1), or preoperative CRT (50.4 Gy in 28 fractions) with 5-FU (250 mg/m2/days 1-14 and 22-35) and oxaliplatin (50 mg/m2/days 1, 8, 22, 29), surgery, and 8 cycles of adjuvant chemotherapy according to modified FOLFOX6 regimen (arm 2). Disease-free survival was the primary endpoint. We present early secondary endpoints, including acute toxicity, treatment compliance, and pCR-rates. Results: 637 patients were randomly assigned to arm 1 and 628 to arm 2. Full dose preoperative RT and full dose concurrent chemotherapy was delivered in 97% and 74% of patients in both arms, respectively. Preoperative grade 3/4 toxicity occurred in 21.6% in arm 1 and in 22.9% in arm 2. The R0-resection rate was 95.4% in both arms, and abdominoperineal resections were limited to 11.9% and 12.2% in arms 1 and 2, respectively. Overall postoperative complications were not different between both arms (21.0% and 21.9%). The pCR rate (ypT0N0) was 13.1% in arm 1 and 17.6% in arm 2 (p = 0.033, Cochran-Mantel-Haenszel Chi-Squared Test without continuity correction for conditional independence of pCR rate in the two treatment arms in each stratum). Conclusions: Inclusion of oxaliplatin to 5-FU based CRT was well tolerated and associated with increased pCR-rates compared with 5-FU-CRT alone. Longer follow-up is necessary to evaluate the primary endpoint, disease-free survival.

Nitrogen-Carbon Interactions in Optical Defects in Silicon

We report five photoluminescence lines N1 through N5 in silicon which emerge after sequential nitrogen and carbon implantation. Studied is in particular the 0.7456 eV (N1) electronic-vibronic spectrum. Single nitrogen and carbon atoms in the defect are identified by isotope shifts of the no-phonon transition and of a local mode satellite with vibration quantum energy ħω= 122.9 meV. Uniaxial stress or Zeeman measurements yield monoclinic I (C1h) or trigonal (C3v) symmetry, respectively, of the optical defect. Comparing the energy of the local mode and its isotope effects with recent literature data on the nitrogen 963 cm−1 IR vibrational absorption line we discuss a defect model involving a substitutional nitrogen atom modified by an interstitial carbon atom.

Origin of the Infrared Band From Porous Silicon

The photoluminescence (PL) infrared (IR)-band of p-doped porous Si (PS) films is studied by steady-state and time-resolved PL and by photoluminescence excitation (PLE) in detail. In analogy to the S-band in the visible the IR-band shifts to higher energies with reduced average nanocrystal size. The IR- and S-bands are very different in their decay behavior and in their recombination lifetimes. The temperature-dependent PL intensity shows non-exponential decay with lifetime distributions in the nsec-µsec range in contrast to the stretched exponential decay shape of the S-band corresponding to lifetime distributions in the μsec -msec range. The origin of the IR-band is likely related to radiative recombination at deep defects in Si nanocrystals with quantum-upshifted band gaps.

Cathodoluminescence Studies of Bound Excitons and Near Band Gap Emission Lines in Boron- and Phosphorus-Doped CVD-Diamonds

Cathodoluminescence measurements at cryogenic temperatures are reported on boron- and phosphorus-doped CVD-diamond films grown on silicon substrates. Boron and phosphorus concentrations were determined by SIMS measurements; for boron, they reached from unintentional background doping levels up to 3500 ppm. At increasing boron concentrations, the radiative recombination of boron bound excitons (BEto) at 5.22 eV photon energy systematically broadens and shifts down to 4.99 eV whereas the free exciton emission (FEto) disappears for 40 ppm and higher. In the phosphorus-doped films we observe new lines at 5.16 eV and 4.99 eV which we ascribe to TO- and (TO+Or)-phonon assisted transitions of an exciton bound to a shallow impurity other than boron, possibly phosphorus or a phosphorus-related shallow complex.

Biological rationales and clinical applications of temperature controlled hyperthermia--implications for multimodal cancer treatments

Hyperthermia (HT)--heating the tumor in the range of 40.0- 44.0 °C--combined with radiation (RT) and/or chemotherapy (CT) is a well proven treatment for malignant tumors. The improvement of the techniques for monitoring and adapting of the desired temperatures even in deep seated tumors has led to a renaissance of, now quality-controlled, HT in multimodal tumor therapy approaches. Randomized clinical trials have shown improved disease-free survival and local tumor control without an increase in toxicity for the combined treatment. In this review, we will focus on biological rationales of HT comprising direct cytotoxicity, systemic effects, chemosensitization, radiosensitization, and immune modulation. The latter is a prerequisite for the control of recurrent tumors and micrometastases. Immunogenic tumor cell death forms induced by HT will be introduced. Modulations of the cytotoxic properties of chemotherapeutic agents by HT as well as synergistic effects of HT with RT will be presented in the context of the main aims of anti-tumor therapy. Furthermore, modern techniques for thermal mapping like magnet resonance imaging will be outlined. The effectiveness of HT will be demonstrated by reviewing recent clinical trials applying HT in addition to CT and/or RT. We conclude that hyperthermia is a very potent radio- as well as chemosensitizer, which fosters the induction of immunogenic dead tumor cells leading to local and in special cases also to systemic tumor control.

[Neoadjuvant radiochemotherapy for rectal cancer]

Neoadjuvant radiochemotherapy has become established treatment for rectal cancer. It is indicated when primary R0 resection is not an option, in cases of higher risk of locoregional relapse following surgical treatment alone, and when initially impossible conservation of the anal sphincter becomes possible in conjunction with neoadjuvant radiochemotherapy. The indication for radiochemotherapy in the upper third of the rectum is still controversial. Reevaluation of the tumor situation following neoadjuvant treatment is necessary before decisions on operative strategy. Modern imaging techniques are limited in this respect, as they hardly allow differentiation between living tumor tissue and lesions. In case of doubt clarity is possible only through surgical exploration, taking R1 resection into account. Overall the recognition of lymph node metastasis is not a sufficient indicator of local relapse. The frequency of postoperative complications following neoadjuvant radiochemotherapy is independent of the operative method. The effect of neoadjuvant radiochemotherapy on long-term survival and formation of distant metastases is still not clarified. Current studies seek clarification through the use of new chemotherapies and modified treatment regimes. Further, the correct time interval between the end of neoadjuvant radiochemotherapy and the following surgical therapy has yet to be determined. This applies also to the management of patients following complete remission.

Technical report: Radiation sensitivity testing by fluorescencein‐situhybridization: how many metaphases have to be analysed?

PURPOSE

The technique of three-colour fluorescence in-situ hybridization (FISH) is generally regarded as 'gold standard' for detecting chromosomal aberrations. The question was: how many metaphases should be counted to get reliable results?

MATERIAL AND METHODS

Peripheral blood lymphocytes were irradiated in vitro (2.0 Gy). Metaphase chromosomes (1, 2, 4) were labelled by means of three-colour FISH and chromosomal aberrations (breaks per metaphase [B/M], complex chromosomal rearrangements per metaphase [CCR/M]) were analysed. To evaluate the correlation between the number of metaphases counted and the reliable detection of the rate of break events, B/M and CCR/M were scored using 250-1,000 metaphases in steps of 50 unirradiated cells, and from 50 to 200 metaphases in steps of 10 after 2 Gy.

RESULTS

Analysing spontaneously occurring aberrations, B/M values based on 500 and 750 counted metaphases agreed well with those B/M values from 1,000 scored metaphases. After counting 150 metaphases after 2 Gy, the confidence interval of B/M values was about 44% smaller and the confidence interval of CCR/M values was about 41% smaller compared with values obtained after counting 100 metaphases.

CONCLUSIONS

Scoring the number of spontaneous aberrations, reliable results can be obtained after counting 500 metaphases. After 2 Gy, a minimum of 150 metaphases should be analysed.

Radiochemotherapy for bladder cancer

Standard treatment for muscle-invasive bladder cancer is cystectomy. Multimodality treatment, including transurethral resection of the bladder tumour, radiation therapy, chemotherapy and deep regional hyperthermia, has been shown to produce survival rates comparable with those of cystectomy. With these programmes, cystectomy has been reserved for patients with incomplete response or local relapse. During the past two decades, organ preservation by multimodality treatment has been investigated in prospective series from single centres and co-operative groups, with more than 1000 patients included. Five-year overall survival rates in the range of 50-60% have been reported, and about three-quarters of the surviving patients maintained their bladder. Clinical criteria helpful in determining patients for bladder preservation include such variables as small tumour size (<5 cm), early tumour stage, a visibly and microscopically complete transurethral resection, absence of ureteral obstruction, and no evidence of pelvic lymph node metastases. On multivariate analysis, the completeness of transurethral resection of a bladder tumour was found to be one of the strongest prognostic factors for overall survival. Patients at greater risk of new tumour development after initial complete response are those with multifocal disease and extensive associated carcinoma in situ at presentation. Close co-ordination among all disciplines is required to achieve optimal results. Future investigations will focus on optimising radiation techniques, including all possibilities of radiosensitisation (e.g. concurrent radiochemotherapy, deep regional hyperthermia), and incorporating more effective systemic chemotherapy, and the proper selection of patients based on predictive molecular makers.