Improved surgical results after combining preoperative hyperthermia with chemotherapy and radiotherapy for patients with carcinoma of the rectum

The measurement and modification of hypoxia in colorectal cancer: overlooked but not forgotten

Tumour hypoxia is the inevitable consequence of a tumour's rapid growth and disorganized, inefficient vasculature. The compensatory mechanisms employed by tumours, and indeed the absence of oxygen itself, hinder the ability of all treatment modalities. The clinical consequence is poorer overall survival, disease-free survival, and locoregional control. Recognizing this, clinicians have been attenuating the effect of hypoxia, primarily with hypoxic modification or with hypoxia-activated pro-drugs, and notable success has been demonstrated. However, in the case of colorectal cancer (CRC), there is a general paucity of knowledge and evidence surrounding the measurement and modification of hypoxia, and this is possibly due to the comparative inaccessibility of such tumours. We specifically review the role of hypoxia in CRC and focus on the current evidence for the existence of hypoxia in CRC, the majority of which originates from indirect positron emission topography imaging with hypoxia selective radiotracers; the evidence correlating CRC hypoxia with poorer oncological outcome, which is largely based on the measurement of hypoxia inducible factor in correlation with clinical outcome; the evidence of hypoxic modification in CRC, of which no direct evidence exists, but is reflected in a number of indirect markers; the prognostic and monitoring implications of accurate CRC hypoxia quantification and its potential in the field of precision oncology; and the present and future imaging tools and technologies being developed for the measurement of CRC hypoxia, including the use of blood-oxygen-level-dependent magnetic resonance imaging and diffuse reflectance spectroscopy.

Heating technology for malignant tumors: a review

The therapeutic application of heat is very effective in cancer treatment. Both hyperthermia, i.e., heating to 39-45 °C to induce sensitization to radiotherapy and chemotherapy, and thermal ablation, where temperatures beyond 50 °C destroy tumor cells directly are frequently applied in the clinic. Achievement of an effective treatment requires high quality heating equipment, precise thermal dosimetry, and adequate quality assurance. Several types of devices, antennas and heating or power delivery systems have been proposed and developed in recent decades. These vary considerably in technique, heating depth, ability to focus, and in the size of the heating focus. Clinically used heating techniques involve electromagnetic and ultrasonic heating, hyperthermic perfusion and conductive heating. Depending on clinical objectives and available technology, thermal therapies can be subdivided into three broad categories: local, locoregional, or whole body heating. Clinically used local heating techniques include interstitial hyperthermia and ablation, high intensity focused ultrasound (HIFU), scanned focused ultrasound (SFUS), electroporation, nanoparticle heating, intraluminal heating and superficial heating. Locoregional heating techniques include phased array systems, capacitive systems and isolated perfusion. Whole body techniques focus on prevention of heat loss supplemented with energy deposition in the body, e.g., by infrared radiation. This review presents an overview of clinical hyperthermia and ablation devices used for local, locoregional, and whole body therapy. Proven and experimental clinical applications of thermal ablation and hyperthermia are listed. Methods for temperature measurement and the role of treatment planning to control treatments are discussed briefly, as well as future perspectives for heating technology for the treatment of tumors.

Quo Vadis Oncological Hyperthermia (2020)?

Heating as a medical intervention in cancer treatment is an ancient approach, but effective deep heating techniques are lacking in modern practice. The use of electromagnetic interactions has enabled the development of more reliable local-regional hyperthermia (LRHT) techniques whole-body hyperthermia (WBH) techniques. Contrary to the relatively simple physical-physiological concepts behind hyperthermia, its development was not steady, and it has gone through periods of failures and renewals with mixed views on the benefits of heating seen in the medical community over the decades. In this review we study in detail the various techniques currently available and describe challenges and trends of oncological hyperthermia from a new perspective. Our aim is to describe what we believe to be a new and effective approach to oncologic hyperthermia, and a change in the paradigm of dosing. Physiological limits restrict the application of WBH which has moved toward the mild temperature range, targeting immune support. LRHT does not have a temperature limit in the tumor (which can be burned out in extreme conditions) but a trend has started toward milder temperatures with immune-oriented goals, developing toward immune modulation, and especially toward tumor-specific immune reactions by which LRHT seeks to target the malignancy systemically. The emerging research of bystander and abscopal effects, in both laboratory investigations and clinical applications, has been intensified. Our present review summarizes the methods and results, and discusses the trends of hyperthermia in oncology.

Therapeutic hyperthermia

The term hyperthermia broadly refers to either an abnormally high fever or the treatment of a disease by the induction of fever. Its effect depends on the temperature and exposure time. The increasing number of applications and clinical trials at universities, clinics, and hospitals prove the feasibility and applicability of clinical therapeutic hyperthermia. This chapter aims to outline and discuss the means by which electromagnetic energy and other techniques can provide elevation of temperature within the human body. Because of the individual characteristic of each type of treatment, different modalities of heating systems have evolved. The chapter concludes with a discussion of challenges and opportunities for further improvement in technology and routine clinical application.

Rad9, Rad17, TopBP1 and claspin play essential roles in heat-induced activation of ATR kinase and heat tolerance

Hyperthermia is widely used to treat patients with cancer, especially in combination with other treatments such as radiation therapy. Heat treatment per se activates DNA damage responses mediated by the ATR-Chk1 and ATM-Chk2 pathways but it is not fully understood how these DNA damage responses are activated and affect heat tolerance. By performing a genetic analysis of human HeLa cells and chicken B lymphoma DT40 cells, we found that heat-induced Chk1 Ser345 phosphorylation by ATR was largely dependent on Rad9, Rad17, TopBP1 and Claspin. Activation of the ATR-Chk1 pathway by heat, however, was not associated with FancD2 monoubiquitination or RPA32 phosphorylation, which are known as downstream events of ATR kinase activation when replication forks are stalled. Downregulation of ATR, Rad9, Rad17, TopBP1 or Claspin drastically reduced clonogenic cell viability upon hyperthermia, while gene knockout or inhibition of ATM kinase reduced clonogenic viability only modestly. Suppression of the ATR-Chk1 pathway activation enhanced heat-induced phosphorylation of Chk2 Thr68 and simultaneous inhibition of ATR and ATM kinases rendered severe heat cytotoxicity. These data indicate that essential factors for activation of the ATR-Chk1 pathway at stalled replication forks are also required for heat-induced activation of ATR kinase, which predominantly contributes to heat tolerance in a non-overlapping manner with ATM kinase.

Pre-operative radiotherapy and curative surgery for the management of localized rectal carcinoma

BACKGROUND

Preoperative radiotherapy (PRT) has become part of standard practice offered to improve treatment outcomes in patients with rectal cancer.

OBJECTIVES

To determine if PRT improves outcome for patients with localized resectable rectal cancer and how it compared with other adjuvant or neoadjuvant strategies.

SEARCH STRATEGY

A computerized search was performed December 2006 on MEDLINE (from 1966 to December 2006) and the Cochrane Central Register of Controlled Trials (CENTRAL), conference proceedings, using MeSH and textwords where appropriate to identify randomized trials in PRT and rectal cancer. In addition, MetaRegister of Clinical Trials was searched for ongoing trials.

SELECTION CRITERIA

Randomized trials with a PRT arm versus surgery alone, or other neoadjuvant or adjuvant (NA/A) strategies, targeted patients with localized rectal cancer planned for radical surgery were included.

DATA COLLECTION AND ANALYSIS

Trials were selected, data extracted and quality assessed by 2 authors. Quality was assessed using a 14 point checklist. Summary statistics included Hazard ratios and variances (for the outcomes: overall (OA) mortality, cause specific (CS) mortality, any recurrence and local recurrences (LR)) and Odds Ratio (OR) for other outcomes. Potential sources of heterogeneity hypothesized a priori included study quality, biological effective dose (BED), radiotherapy RT technique, and total mesorectal excision (TME) surgery.

MAIN RESULTS

Nineteen trials compared PRT versus surgery alone. Overall (OA) mortality was marginally improved HR 0.93 [95% CI -0.87-1](absolute difference is 2% if the expected survival rate is 60%). Local recurrence (LR) was improved but the magnitude of benefit was heterogeneous across trials. Sensitivity analyses suggested greater benefits in patients treated with BED>30Gy(10) and multiple field RT techniques. There was significantly more pelvic or perineal wound infection, late rectal and sexual dysfunction. Nine trials compared PRT vs. other NA/A. Available evidence did not support an OA mortality or sphincter preserving benefit with the use of combined chemoradiotherapy (CRT) or selective postoperative RT. CRT provides incremental benefit for local control compared with PRT, which was independent of the timing of the CT. There was no significant difference in outcome for different intervals between RT and surgery (2 vs. 8 wk). Dose escalation with endocavitary boost showed significant effect on sphincter preservation.

AUTHORS' CONCLUSIONS

Optimal PRT improves LR, OA mortality, but no increase in sphincter sparing procedure. CRT further increases local control. If the objective is to increase the incidence of sphincter sparing surgery, endocavitary boost showed the most promise. Strategies with the potential to improve outcomes, especially OAS and sphincter sparing while reducing acute and late toxicities (rectal and sexual function) are needed to guide future strategy designs.

Influence of neoadjuvant radiochemotherapy combined with hyperthermia on the quality of life in rectum cancer patients

PURPOSE

The present study compares quality of life (QoL) after neoadjuvant radiochemotherapy with or without hyperthermia in patients with advanced rectal cancer.

METHODS

Between April 1994 and May 1999, 137 patients were treated by neoadjuvant radiochemotherapy with (69 patients (50.4%)) or without (68 patients (49.6%)) hyperthermia. Forty-six patients (33.6%) filled-out a 'Gastrointestinal Quality of Life Index' (GIQLI) questionnaire at four time points (before and after neoadjuvant therapy, early after surgery and after long-term follow-up) and were included in the present study.

RESULTS

There were no statistically significant differences in the global GIQLI index between patients treated with neoadjuvant radiochemotherapy with and without hyperthermia at any time point. The longitudinal analysis of GIQLI values in both treatment groups showed specific profiles that were identical in both treatment groups. Occurrence of severe toxicity during the neoadjuvant therapy in both arms lead to a significant temporary reduction of QoL scores at TP2 without any detrimental long-term effects. Patients with sphincter preservation and patients with sphincter resection reported similar QoL scores during long-term follow-up.

CONCLUSION

Neoadjuvant radiochemotherapy with and without hyperthermia has similar effects on the QoL of patients with locally advanced rectal cancer. The addition of hyperthermia during the neoadjuvant therapy with the potentially associated inconveniences has no negative effects on QoL.

Radiotherapy with 8 MHz radiofrequency-capacitive regional hyperthermia for pain relief of unresectable and recurrent colorectal cancer

PURPOSE

The purpose of this study was to assess the pain relief in patients with unresectable and recurrent colorectal cancer treated with radiation plus 8 MHz radiofrequency-capacitive regional hyperthermia and to identify predictors of the good outcome.

METHODS

Between February 1986-May 2003, 41 patients with primarily unresectable and recurrent colorectal cancer that caused pain were treated with thermoradiotherapy at the hospital and retrospectively analysed. Radiotherapy was administered with a mean total radiation dose of 56 Gy. Hyperthermia was usually applied within 30 min after radiotherapy once or twice a week. For cooling of the skin surface, the overlay boluses were applied in addition to regular boluses. The external cooling unit has been used to reinforce the cooling ability of the overlay bolus and achieve strong surface cooling to reduce the preferential heating of the subcutaneous fat tissue and treat with more RF-output in 17 patients since January 1997.

RESULTS

Pain relief was obtained in 83% of the patients. Multi-variate analysis by logistic regression to evaluate the effects of certain factors on pain relief (complete response + good response) was strongly correlated with the presence of radiating pain to leg(s) (p < 0.05). The median follow-up was 18 months. The median duration of pain relief was 7.0 months. For the 27 patients in whom the tumour temperature was estimated, the median duration of pain relief was 14.6 months for the patients with a mean average tumour temperature of > 42.5 degrees C and 5.7 months for those of < 42.5 degrees C (p < 0.05). In the 18 patients with radiating pain to leg(s), use of strong superficial cooling and the higher numbers of hyperthermia treatments were better prognostic factors for the duration of pain relief (p < 0.01 and p < 0.05, respectively).

CONCLUSIONS

Radiotherapy with 8 MHz radiofrequency-capacitive regional hyperthermia provided an efficient, effective means on pain relief of treating unresectable and recurrent colorectal cancer. The duration of pain relief can be prolonged, if an adequate heating is achieved, especially in the patients with radiating pain to the leg(s).

Efficacy of preoperative radiation therapy for resectable rectal adenocarcinoma when combined with oral tegafur-uracil modulated with leucovorin: results from a phase II study

PURPOSE

The aim of this study was to evaluate the efficacy of preoperative radiation therapy for resectable rectal adenocarcinoma (T3-T4) when delivered in combination with chemotherapy (oral tegafur-uracil modulated with leucovorin).

METHODS

Thirty-eight patients (23 males; mean age, 62 years.) with histologically proven rectal adenocarcinoma with primary tumor clinical classification T3-T4 (resectable) and N0 or N1-N2, according to TNM staging system, took part in the present clinical trial. After tumor and metastasis resectability confirmation, radiation therapy was administered by delivering a dose of 45 Gy in 25 fractions for 5 weeks. Chemotherapy treatment was initiated on the same day as radiotherapy and consisted of intravenous infusion of 6S-steroisomer of leucovorin 250 mg/m /day in 2 hours on Day 1, followed by oral 350 or 300 mg/m /day of tegafur (a 5-fluorouracil prodrug) plus uracil on Days 1 to 14 divided into 2 daily doses, and oral 6S-steroisomer of leucovorin 7.5 mg/12 hours on Days 2 to 14, with a total of 102 courses of neoadjuvant chemotherapy (, mean of 2.7 courses per patient). Six additional courses of tegafur-uracil were given postoperatively to all 38 patients but 1 who refused.

RESULTS

As a result of preoperative chemoradiation treatment, 4 (10.5 percent) complete responses, 20 (52.6 percent) partial responses, and 14 (36.8 percent) patients with disease stabilization were observed. No patients had preoperative disease progression. Histologically proven downstaging was observed in 23 (60 percent) patients. On initial evaluation, only 39 percent of patients were considered as being good candidates for sphincter-preserving surgery; however, on preoperative chemoradiation completion this figure increased up to 60 percent. For the 23 patients eventually undergoing sphincter-preserving surgery, postoperative sphincter function assessment showed excellent function in 15 (65 percent) patients, good in 5 (22 percent), fair in 2 (9 percent), and poor in 1(4 percent). With a median follow-up of 37 (range, 10-62) months, local failure was found in 3 (8 percent) patients and distant failure in 2 (5 percent). Three-year actuarial disease-free survival and 3-year overall survival rates were 83 and 90 percent, respectively. Local control rate was 92 percent. Toxicity and postoperative complication rates were reasonable.

CONCLUSIONS

Our neoadjuvant radiation therapy protocol is efficient for the preoperative treatment of resectable rectal adenocarcinoma when combined with chemotherapy (oral tegafur-uracil modulated with leucovorin). this protocol needs to be tested in a phase-III clinical trial with a larger sample size.

Heating the patient: a promising approach?

There is a clear rationale for using hyperthermia in cancer treatment. Treatment at temperatures between 40 and 44 degrees C is cytotoxic for cells in an environment with a low pO(2) and low pH, conditions that are found specifically within tumour tissue, due to insufficient blood perfusion. Under such conditions radiotherapy is less effective, and systemically applied cytotoxic agents will reach such areas in lower concentrations than in well perfused areas. Therefore, the addition of hyperthermia to radiotherapy or chemotherapy will result in at least an additive effect. Furthermore, the effects of both radiotherapy and many drugs are enhanced at an increased temperature. Hyperthermia can be applied by several methods: local hyperthermia by external or internal energy sources, regional hyperthermia by perfusion of organs or limbs, or by irrigation of body cavities, and whole body hyperthermia. The use of hyperthermia alone has resulted in complete overall response rates of 13%. The clinical value of hyperthermia in addition to other treatment modalities has been shown in randomised trials. Significant improvement in clinical outcome has been demonstrated for tumours of the head and neck, breast, brain, bladder, cervix, rectum, lung, oesophagus, vulva and vagina, and also for melanoma. Additional hyperthermia resulted in remarkably higher (complete) response rates, accompanied by improved local tumour control rates, better palliative effects and/or better overall survival rates. Generally, when combined with radiotherapy, no increase in radiation toxicity could be demonstrated. Whether toxicity from chemotherapy is enhanced depends on sequence of the two modalities, and on which tissues are heated. Toxicity from hyperthermia cannot always be avoided, but is usually of limited clinical relevance. Recent developments include improvements in heating techniques and thermometry, development of hyperthermia treatment planning models, studies on heat shock proteins and an effect on anti-cancer immune responses, drug targeting to tumours, bone marrow purging, combination with drugs targeting tumour vasculature, and the role of hyperthermia in gene therapy. The clinical results achieved to date have confirmed the expectations raised by results from experimental studies. These findings justify using hyperthermia as part of standard treatment in tumour sites for which its efficacy has been proven and, furthermore, to initiate new studies with other tumours. Hyperthermia is certainly a promising approach and deserves more attention than it has received until now.

Neoadjuvant therapy of rectal carcinoma with UFT-leucovorin plus radiotherapy

BACKGROUND

The object of this phase II study was to assess the impact of preoperative external radiation therapy combined with UFT and leucovorin on tumor response, sphincter preservation and tumor control in patients with rectal carcinoma.

PATIENTS AND METHODS

Forty-one patients with resectable extraperitoneal rectal adenocarcinoma received radiation therapy and two courses of chemotherapy. Chemotherapy consisted of a 2-h infusion of 6S-steroisomer of leucovorin (6SLV) 250 mg/m2 on day 1, oral 6SLV 7.5 mg every 12 h on days 2-14, and UFT either 350 or 300 mg/m2 on days 1 to 14 every 28 days. Six additional courses of chemotherapy were given after surgery.

RESULTS

Seven of 16 patients (43%) who received 350 mg/m2/day of UFT had grade 3-4 diarrhea and two other patients (12%) had grade 3-4 dermatitis. The next 25 patients received 300 mg/m2/day of UFT and only 14% of them had grade 3-4 diarrhea. Surgery consisted of low-anterior resection in 26 patients (63%) and abdominal-perineal amputation in 15 (37%). There were six histological complete responses (15%). Downstaging occurred in 25 patients (63%). The overall survival at 3 years was 90% and the pelvic disease-free survival 92%.

CONCLUSIONS

Preoperative therapy with radiotherapy and UFT-6SLV downstaged 63% of tumors and allowed a sphincter-preserving procedure in some patients. Toxicity was moderate. This scheme is convenient because of the oral administration of chemotherapy.

Hyperthermia for rectal cancer

BACKGROUND

In order to improve the clinical results of rectal cancer, hyperthermia has been prescribed in combination with chemotherapy and radiotherapy. The techniques of hyperthermia and their clinical applications to rectal cancer were reviewed.

METHODS

The development of heating devices has been intensively investigated, including external heating devices, intraluminal heating devices, circulation of warmed saline solution, and whole body hyperthermia.

RESULTS

Nonrandomized and randomized trials for rectal cancer have demonstrated an improved local response with the combined use of hyperthermia and conventional treatments. A preoperative therapy with hyperthermia increased resectability and decreased local recurrence, resulting in the improvement of the postoperative prognosis. There were no major postoperative complications related to the preoperative treatment. A lower incidence of local recurrence was observed in groups that underwent intra- or postoperative hyperthermia treatment, as compared with control groups. In cases with unresectable or local recurrent rectal cancer, hyperthermia achieved a local tumor regression and prolonged pain relief.

CONCLUSIONS

These clinical data suggest that hyperthermia combined with radiation or chemotherapy demonstrates great promise for the treatment of patients with carcinoma of the rectum.

Clinical application of hyperthermia combined with anticancer drugs for the treatment of solid tumors

BACKGROUND

Hyperthermia is one of the modalities used to treat various forms of malignancies, including esophageal, stomach, or rectal cancers.

METHODS

The basic mechanism of synergism between hyperthermia and anticancer drugs, as well as the clinical result of hyperthermia for the treatment of gastrointestinal malignancy, was reviewed.

RESULTS

Hyperthermia exerts a cytotoxic effect in combination with various mechanisms. Hyperthermia is applied in combination with chemotherapy and/or radiotherapy in the clinical setting. Among the anticancer drugs that are synergistic with hyperthermia is cisplatin, which is prevalent for clinical application. The mechanism of enhanced cytotoxicity of cisplatin includes increased intracellular drug accumulation, increased platinum-DNA adducts, and inhibition of DNA repair. At our institute, hyperthermochemoradiotherapy was conducted as a neoadjuvant therapy for either operative cases or as a palliative therapy for unresectable cases for esophageal and rectal cancers. In both situations, hyperthermochemoradiotherapy showed an excellent benefit in both the control of local recurrence and and in an improvement in patient survival. Regarding gastric cancer, the most popular application of hyperthermia was the intraoperative hyperthermic peritoneal lavage with cisplatin. This treatment modality demonstrated a better control of the disseminated lesion. Regarding the factors that influence thermosensitivity, in vitro experiments demonstrated the heat-shock proteins or tumor suppressor gene p53 to be related to thermosensitivity. In the clinical setting, these factors remain to be firmly established as predictive factors for thermosensitivity.

CONCLUSIONS

It is evident that hyperthermia was effective in the control of far-advanced gastrointestinal malignancies. When more reliable factors for the prediction of the treatment response can be established, the standard guidelines for the application of hyperthermia can then be made.

Combined modality therapy of rectal cancers

Rectal cancer accounts for about 10% of new cancer cases each year. It strikes men and women at nearly the same rate, generally in the range of 50-80 years of age, with rising incidence with age. Despite simple screening procedures rectal cancer is often advanced when discovered. Current trends in the management of cancer have focused on organ preservation and improved quality of life without compromising the overall survival. During the last decade substantial progress has been made in treatment modalities: new and improved radiation techniques (conformal radiotherapy, altered fractionation, brachytherapy), chemotherapy (protracted infusion, use of radiosensitizers) and development of surgical procedures-enabling safer postoperative irradiation. In patients with advanced/unresectable disease aggressive combined chemoradiation can be added prior to surgery to downstage the tumour and increase the proportion treated with anal-rectal-sparing procedures. Preoperative chemoradiation therapy regimens are as safe and tolerable as the standard postoperative treatment. In this presentation indications for preoperative radiochemotherapy will be discussed in detail, together with treatment-related side effects, prognostic parameters, tumour response and outcome. Different irradiation settings and chemotherapy schedules are described. In patients with primary resectable disease (mainly Dukes C) several prospective randomised trials have shown less local recurrence with postoperative combined modality therapy.