Long-term survival after photodynamic therapy for esophageal cancer

Surgery, radiotherapy, and chemotherapy in carcinoma of the esophagus

Esophageal carcinoma remains a highly lethal disease that has shown a recent profound increase in prevalence and an equally dramatic epidemiologic shift. There is a well recognized causal association between gastroesophageal reflux disease and adenocarcinoma of the esophagus, and the molecular events underlying this progression from mucosal injury, to metaplasia, to dysplasia, to carcinoma are now becoming clear. Current diagnostic modalities and preoperative staging systems all have significant limitations. Fortunately, chemoprevention strategies and the identification of clinically useful molecular biomarkers that may be used to stage disease and select appropriate therapy are on the horizon. The extent of surgical resection for esophageal carcinoma remains an area of great controversy. Disease that is confined to the mucosa is being diagnosed more commonly, and endoscopic ablative techniques have been proposed. To date, however, preoperative discrimination of tumor depth and presence of regional nodal metastases remains inadequate in these very early lesions, and caution is urged before adopting therapies that may compromise cure. For disease penetrating the mucosa, the extent of surgical therapy must be tailored by the objectives of treatment (cure vs palliation) and preoperative stage. Surgical resection is the current standard of care, with combined-modality therapy reserved for prohibitive surgical candidates. No clear survival benefit has been documented for neoadjuvant radiotherapy or chemotherapy alone. The results of preoperative combined-modality therapy, including three prospective, randomized trials, are encouraging but to date have not shown a definite benefit.

Outcome of patients receiving photodynamic therapy for early esophageal cancer

PURPOSE

Photodynamic therapy (PDT) has shown remarkable activity in a variety of human cancers. In the present study, we report the effects of PDT on inoperable early-stage esophageal cancer.

METHODS AND MATERIALS

Sixty-two patients were treated with an argon dye laser (630 nm wavelength, 300-800 mW of power, energy dose of 200-300 J/cm) after intravenous injection of 5 mg/kg of hematoporphyrin derivative. Eighteen patients (29.5%) had in situ carcinoma (Tis), 30 (48.5%) had T1-stage cancer, 7 (11%) had T2-stage cancer, and 7 (11%) had recurrent disease in the anastomotic area after previous surgery without evidence of invasion outside the lumen. Patients with residual disease after two rounds of PDT received definitive radiotherapy. Patients were evaluated for response to therapy and survival. The follow-up time ranged from 3 to 90 months (median, 32 months).

RESULTS

The complete response (CR) rate was 37% (23 of 62) in patients who received PDT alone and 82% (51 of 62) in those who also received radiotherapy. The CR rate after PDT alone was statistically higher (p = 0.04) for patients who had Tis/T1 lesions (21 of 48; 44%) than for those with T2-stage disease (2 of 7; 28%) or recurrent tumors (0 of 7; 0%). Fifty-two percent of patients who had CR following PDT alone did not suffer local tumor recurrence. The median local progression-free survival times after PDT and additional radiotherapy (in cases with incomplete response) was 49 months for Tis- and T1-stage lesions, 30 months for those with T2-stage disease, and 14 months for patients with locally recurrent disease. Patients who completely responded to PDT had a median overall survival (OS) of 50 months, which was significantly longer (p < 0.003) than that of patients not responding to PDT. Toxicity was minimal; we recorded three cases of esophageal stenosis (7%) and one case of tracheo-esophageal fistula (2.5%) after combined PDT and radiotherapy.

CONCLUSION

PDT is an effective regimen for early esophageal cancer, giving a CR rate of about 40%, long-term local control and favorable overall survival. Additional radiotherapy in cases of incomplete response to PDT is effective and potentially curative in another 45% of cases.

Hyperbaric oxygen and photodynamic therapy in the treatment of advanced carcinoma of the cardia and the esophagus

BACKGROUND AND OBJECTIVE

The photochemical reaction of photodynamic therapy (PDT) depends on the presence of molecular oxygen. Because of anoxic regions in tumor tissue and vascular shutdown during PDT, the efficiency is limited. Therefore, the use of hyperbaric oxygen, which increases the oxygen in tumor tissue, as well as the amount of singlet oxygen, may enhance the efficiency of PDT.

STUDY DESIGN/MATERIALS AND METHODS

After diagnostic work-up, photosensitization was carried out with a hematoporphyrin-derivate 2 mg/kg body weight 48 hours before PDT. The light dose was calculated as 300 J/cm of fiber tip. Twenty-three patients were treated by PDT alone and 29 patients received PDT under hyperbaric oxygen at a level of two absolute atmospheric pressures.

RESULTS

Improvement regarding dysphagia and stenosis-diameter could be obtained in both treatment arms with no significant difference (P = 0.43 and P = 0. 065, respectively). The tumor length also decreased in both groups and showed a significant difference in favour of the PDT/HBO group (P = 0.002). The mean overall survival was 11.3 months. The mean survival time for the PDT group was 8.7 months and for the PDT/HBO group 13.8 months (P = 0.021).

CONCLUSION

According to this pilot study, combined PDT/HBO represents a new approach in the treatment of esophageal and cardia cancer, which appears to have enhanced the efficiency of PDT.

Endoscopic mucosal resection of early cancer and high-grade dysplasia in Barrett's esophagus

BACKGROUND & AIMS

In view of the mortality and morbidity rates of esophagectomy and the relatively large group of inoperable patients, local therapeutic techniques are required for high-grade dysplasia and early Barrett's cancer.

METHODS

A prospective investigation of endoscopic mucosal resection was conducted in 64 patients (mean age, 65 +/- 10 years) who had early carcinoma (61 patients) or high-grade dysplasia (3 patients) in Barrett's esophagus. Thirty-five patients met the criteria for low risk: macroscopic types I, IIa, IIb, and IIc; lesion diameter up to 20 mm; mucosal lesion; and histological grades G1 and G2 and/or high-grade dysplasia (group A). The remaining 29 patients were included in group B (high risk).

RESULTS

A total of 120 resections were performed, with no technical problems encountered. The mean number of treatment sessions per patient was 1. 3 +/- 0.6 in group A and 2.8 +/- 2.0 in group B (P < 0.0005). Only one major complication occurred, a case of spurting bleeding, which was managed endoscopically. Complete local remission was achieved significantly earlier (P = 0.008) in group A than in group B. In May 1999, complete remission had been achieved in 97% of the patients in group A and in 59% of those in group B; however, 1 patient in group A and 9 in group B are still undergoing treatment or awaiting the first check-up. During a mean follow-up of 12 +/- 8 months, recurrent or metachronous carcinomas were found in 14%.

CONCLUSIONS

Endoscopic mucosal resection of early carcinoma in Barrett's esophagus is associated with promisingly low morbidity and mortality rates. The procedure may offer a new minimally invasive therapeutic alternative to esophagectomy, especially in low-risk situations. Comparisons with surgical results will need to be done when the long-term results of this procedure become available.

Palliation of advanced esophageal carcinoma by photodynamic therapy and irradiation

BACKGROUND

We wanted to determine the role of photodynamic therapy in a multimodal approach for the treatment of patients with advanced cancer of the esophagus.

METHODS

We reviewed the cases of 119 patients with nonresectable esophageal carcinoma who underwent endoluminal palliation. Twenty-one patients required initial dilation and tumor obliteration with a neodymium: yttrium-aluminum-garnet laser prior to therapy. Forty-four patients received photodynamic therapy followed by brachyradiotherapy, and 75 patients were treated with brachyradiotherapy. In both groups, some patients also received external-beam irradiation.

RESULTS

Photodynamic therapy produced a significant difference in relieving stenosis caused by tumor stenosis (mean, 6.6 mm; p = 0.0000). The dysphagia score improved by one to three levels in all patients, with a significant difference in favor of PDT (p = 0.0003). The mean number of overall treatment sessions was four (range, one to seven). The rate of major complications was 9.2%. Four esophageal perforations occurred, three after intervention and one spontaneously 5 months later. Four esophagorespiratory tract fistulas developed several months after combined PDT and irradiation. The mean overall survival was 7.7 months, and analysis of variance revealed a significant difference in favor of PDT and external-beam irradiation (p = 0.0129 and p = 0.0001, respectively).

CONCLUSIONS

Photodynamic therapy has been shown to be an effective palliative treatment of advanced esophageal cancer. However, proper patient selection is necessary to prevent serious complications.

ARGON PLASMA COAGULATION FOR THE ENDOSCOPIC TREATMENT OF A NON‐RESECTABLE KLATSKIN TUMOR: IN VITRO AND IN VIVO STUDY

Background: Palliative treatment including stenting is limited in patients with Klatskin tumor. Argon plasma coagulation (APC) is a new local treatment modality for the devitalization and debulking of tumors. Argon plasma coagulation could be a candidate method for relief of biliary strictures in patients with non‐resectable Klatskin tumor in whom biliary stenting has failed. This study provides an evaluation of the technical feasibility, safety, and effect of APC as a palliative strategy in patients with non‐resectable Klatskin tumor.

Methods: In vitro studies were performed in order to investigate the dimension of coagulation necrosis in 11 human gallbladders. The currents were applied in normal air conditions and a bowl filled with normal saline in five and six specimens, respectively. Argon plasma coagulation was also performed on three patients with Klatskin tumor who showed no effective drainage via percutaneous transhepatic approach with a cholangioscope.

Results: A coagulation current was delivered to the specimen even if in normal saline. The maximum depth and diameter of necrosis was 3 and 6.5 mm under normal air conditions, compared with 2 and 5 mm in water conditions. No perforation of the gallbladder wall occurred in any of the lesions. The dimension of the necrosis increased with increasing impact time and energy settings. Argon plasma coagulation application was possible on tumors of patients without severe complication.

Conclusion: Argon plasma coagulation seems to be applicable, effective and relatively safe in palliative treatment for advanced non‐resectable Klatskin tumor via cholangioscopy. Longer follow ups and comparative trials with other treatment modalities are, however, required.

Photodynamic therapy

Photodynamic therapy (PDT) is a treatment modality that utilizes a photosensitizing drug activated by laser-generated light and is proving effective for oncologic and nononcologic applications in the gastrointestinal tract. This article provides an overview of the most frequently used photosensitizers and clinical PDT studies in the upper gastrointestinal tract. In the future, the best indications for PDT in the esophagus will not comprise the palliative treatment of obstructing tumors but precancerous lesions such as Barrett's esophagus with or without dysplasia and early cancer. PDT might establish itself as a minimally invasive treatment alternative compared with surgery for high-grade dysplasia or early mucosal cancer of the esophagus.

Neoadjuvant photodynamic therapy before curative resection of proximal bile duct carcinoma

BACKGROUND

Hilar bile duct carcinoma has an 80% probability of local recurrence after curative resection, which might be reduced if neoadjuvant photodynamic therapy is feasible. CASE AND TREATMENT: After intravenous injection of sodium porfimer we treated an adenocarcinoma of the proximal common bile duct (T2 N0 M0, Bismuth type II) in a 72-year-old man with red laser light (applied from the lumen at a dose 250 Joules/cm2), and the adjacent right and left hepatic and common bile duct at a dose of 125 Joules/cm2. After 23 days the tumor was completely resected (adenocarcinoma pT2 pNO; G2).

RESULTS

In the lumenal, 4-mm-thick layer the bile duct specimen exhibited complete tumor necrosis with pigmentation of photodegraded porfimer and no viable tumor cells, while in the outer layer of the wall (at 5-8-mm depth) viable cancer cell nests without degraded porfimer were seen. The bile duct tissue showed little damage. Eighteen months after surgery, neither tumor recurrence nor stricture formation was found at the pretreated bilioenteric anastomoses.

CONCLUSIONS

a) Photodynamic therapy with sodium porfimer seems to be confined to the superficial 4-mm layer of bile duct cancer. b) Neoadjuvant photodynamic therapy is feasible for hilar bile duct carcinoma.

Photodynamic therapy for advanced bile duct cancer: evidence for improved palliation and extended survival

Median survival time of nonresectable hilar bile duct cancer is only 4 to 6 months owing to tumor spread in the biliary tree, refractory cholestasis, and sepsis or liver failure. We explored whether local photodynamic therapy of nonresectable bile duct cancer could improve survival. A sample size of 23 patients is required to detect an increase in 6-month survival rate from less than 50% to greater than 70% in a single-arm phase-II trial with a statistical power of 80% (Fleming's single step procedure; alpha = 0.05). Twenty-three consecutive patients (8 women, 15 men; 67 +/- 14 years) with nonresectable bile duct cancer (Bismuth type III n = 2, type IV n = 21) were treated with photodynamic therapy and biliary endoprosthesis. Photofrin (QLT Pharmaceuticals, Vancouver, Canada) (2 mg/kg body weight intravenously) was photoactivated after 1 to 4 days with laser light (630 nm; 242 J/cm(2)) via endoscopic retrograde access. The 6-month survival rate was 91% after diagnosis and 74% after start of photodynamic therapy (30-day mortality rate was 4%) at a median follow-up time of 10.3 months after diagnosis. Causes of death were tumor progression (n = 9) and bacterial infections (n = 4). The median rate of local tumor response was 74%, 54%, 29%, and 67% after the first, second, third, fourth, and fifth photodynamic therapy. Time to progression ranged from 3 to 8 months. All patients, except 1 with diffuse liver metastases, improved in cholestasis, performance, and quality of life. Photodynamic therapy can prevent tumor occlusion of hilar bile ducts. The apparent benefit in survival time should be confirmed in a controlled trial versus palliation by endoprosthesis only.

Photodynamic therapy in gastrointestinal cancer: a realistic option?

Photodynamic therapy is now a useful and practical option of the local treatment of gastrointestinal cancers. There is increasing screening and surveillance of patients at risk of oesophageal and gastric cancers. The early detection of disease is often unhelpful if an elderly or frail patient needs to be subjected to radical resectional surgery. Photodynamic therapy can eradicate and cure early mucosal disease following a single endoscopic treatment. If the disease is more advanced good local control and palliation is often possible. Overall, palliation can often be achieved using simpler methods which are highly effective and not associated with the problems of prolonged photosensitisation. It is rapidly becoming clear that the ideal indication is for the treatment of dysplastic lesions in the oesophagus associated with columnar-lined oesophagus (Barrett's oesophagus). In these circumstances a heterogeneous field change often with multifocal dysplasia or cancer can be widely eradicated. Similar areas of squamous dysplasia in the upper oesophagus can be treated. At present a major complication of stricture formation is associated with the use of some photosensitisers. The treatment of cancer at the ampulla of Vater and choriocarcinoma is also proving very effective. The treatment can be performed at endoscopy and is well tolerated and safe.

Photodynamic therapy using 5-aminolaevulinic acid for oesophageal adenocarcinoma associated with Barrett's metaplasia

Photodynamic therapy (PDT) is a novel technique for local endoscopic treatment of gastrointestinal neoplasia. Current photosensitisers for PDT may cause prolonged skin phototoxicity. 5-Aminolaevulinic acid (ALA), a precursor of the photosensitiser protoporphyrin IX (PpIX), is more acceptable because of its short half-life and preferential accumulation in mucosa and mucosal tumour. We have treated 12 patients, median age 73 years (range 55-88) with oesophageal adenocarcinoma arising from Barrett's metaplasia (two carcinomas-in-situ, grade 0; 10 carcinomas, grade 1-11A based on endoluminal ultrasound in two and CT scanning in 10 patients). ALA (60 and 75 mg/kg body weight) was given orally in two or five equally divided doses. The PpIX distribution in stomach, normal oesophagus, Barrett's mucosa and carcinoma was measured by quantitative fluorescence photometry. PDT was performed using laser light (630 nm) delivered via a cylindrical diffuser 4-6 h after the first dose of ALA. The patients received one to four sessions of PDT. PpIX accumulation in the mucosa was two to three times that in the lamina propria. The differential distribution between carcinomatous and normal oesophageal mucosa was less marked (carcinoma:normal mucosa ratio = 1.4). Higher doses of ALA increased PpIX accumulation in all tissues but did not increase the differential PpIX distribution between tumour and normal oesophageal mucosa. After PDT using ALA (ALA/PDT), all mucosa showed superficial white necrotic changes and the histology confirmed fibrinoid necrosis. One patient with carcinoma-in-situ had the tumour eradicated after one treatment with no recurrence at 28 months. Another patient with a small T1 tumour required four ALA/PDT treatments, and died of other disease after 36 months. There was no evidence of recurrence. The tumour bulk in the other carcinomas was not significantly reduced. ALA/PDT has a potential for the eradication of small tumours but careful patient selection with endoluminal ultrasound is needed when using ALA/PDT to treat oesophageal cancer.

Endoscopic ultrasonography in patients with gastro-esophageal cancer

For patients with gastro-esophageal cancer ultrasonography (EUS) is superior to any other imaging modality in the assessment of local tumor infiltration and local lymph nodes status. EUS is especially important in the preoperative staging of patients with esophageal cancer and patients with proximal gastric cancer. Here it allows for the identification of those patients with advanced disease who are unlikely to benefit from surgery and in whom a conservative palliative treatment is indicated. In advanced gastric cancer the clinical implications of EUS less clear. Still preoperative EUS is indicated in every patient with cancer of the proximal stomach to assess tumor infiltration in the esophagus. Relatively new is the use of EUS in staging early cancers in order to select patients for local endoscopic treatment. High-frequency miniprobes are the instruments of choice for imaging these lesions. Strict criteria should be applied in the selection of patients for local endoscopic treatment of early gastro-esophageal cancers. EUS guided fine needle aspiration (EUS-FNA) is currently only indicated in patients with esophageal cancer and suspicious celiac lymph nodes. It may become more important if new treatment protocols demand more objective and reliable assessment of lymph node status.

[Barrett's esophagus and antireflux surgery: a study of a series of 26 patients]

STUDY AIM

The aim of this study was to report the results of a retrospective series of 26 patients with Barrett's esophagus treated by antireflux surgery.

PATIENTS AND METHODS

From 1979 to 1998, 21 men and five women (mean age: 53 years) with histologically proven Barrett's esophagus underwent an antireflux procedure. The mean length of Barrett's epithelium was 5.9 cm for 19 patients (73.1%). Six patients (23.1%) had tongue lesions of Barrett's epithelium, and one (3.8%) had ectopic gastric mucosa. None of the patients had a preoperative esophageal biopsy that revealed high-grade dysplasia or carcinoma. Laparotomy was performed in 17 cases and laparoscopy in nine cases. Preoperative endoscopic local treatment with argon coagulation was performed in one patient.

RESULTS

Clinical mean follow-up was 78 months and endoscopic mean follow-up was 59.3 months. No increase in the length of the Barrett's epithelium was observed. Seven patients (27%) had complete or partial regression (among them three patients with tongue lesions and one patient preoperatively treated by argon). No patients developed high-grade dysplasia or carcinoma.

CONCLUSION

Regression of Barrett's esophagus is possible but not frequent and unpredictable after antireflux procedure. However, endoscopic and histological surveillance should be continued postoperatively.

Current concepts in gastrointestinal photodynamic therapy

OBJECTIVE

To review current concepts of photodynamic therapy (PDT) applied to the treatment of tumors of the gastrointestinal tract.

SUMMARY BACKGROUND DATA

PDT initially involves the uptake or production of a photosensitive compound by tumor cells. Subsequent activation of the photoreactive compound by a specific wavelength of light results in cell death, either directly or as a result of vascular compromise and/or apoptosis.

METHODS

The authors selectively review current concepts relating to photosensitization, photoactivation, time of PDT application, tissue selectivity, sites of photodynamic action, PDT effects on normal tissue, limitations of PDT, toxicity of photosensitizers, application of principles of PDT to tumor detection, and current applications of PDT to tumors of the gastrointestinal tract.

RESULTS

PDT is clearly effective for small cancers, but it is not yet clear in which cases such treatment is more effective than other currently acceptable approaches. The major side effect of PDT is cutaneous photosensitization. The major limitation of PDT is depth of tumor kill. As data from current and future clinical trials become available, a clearer perspective of where PDT fits in the treatment of cancers will be gained. Many issues regarding pharmacokinetic data of photosensitizers, newer technology involved in light sources, optimal treatment regimens that take advantage of the pharmacophysiology of photoablation, and light dosimetry still require solution. One can foresee application of differing sensitizers and light sources depending on the specific clinical situation. As technologic advances occur, interstitial PDT may have significant application.

CONCLUSIONS

PDT has a potentially important role either as a primary or adjuvant mode of treatment of tumors of the gastrointestinal tract.

Photodynamic therapy of cancer of the esophagus using systemic aminolevulinic acid and a non laser light source: a phase I/II study

BACKGROUND

Surgery is the mainstay for the treatment of carcinoma of the esophagus and is also considered to be effective for palliation of dysphagia. Patients who are unfit for surgery represent a difficult therapeutic problem. The goal of the present study was to evaluate the effects of photodynamic therapy by using systemic administration of 5-aminolevulinic acid and a non laser light source on carcinoma of the esophagus.

METHODS

Patients were given 60 mg/kg 5-aminolevulinic acid orally. Twenty-four hours later gastroscopy was performed. After initial localization of the tumor with the use of white light, the light source was switched to the red light band at 100 J/cm2 for 600 seconds. Gastroscopy was repeated at 48 hours and 7 days after the treatment. The degree of dysphagia was recorded before and 14 days after treatment.

RESULTS

Five patients with advanced nonresectable tumors or who were unfit for surgery were treated. Two patients had squamous cell carcinoma of the mid-esophagus and three had adenocarcinoma of the distal esophagus. Mild self-limiting photosensitivity was noted in all patients. Liver and renal function tests as well as hemoglobin level and white blood cell count were not affected by the treatment. Improvement of dysphagia was observed in four patients who had pretreatment dysphagia. The patient with the early stage of disease continued to eat a normal diet.

CONCLUSIONS

Photodynamic therapy with systemic aminolevulinic acid as a photosensitizer and a non laser light source is feasible and safe in advanced-stage esophageal cancer. It can be an effective modality for the relief of dysphagia in these patients.

Photodynamic therapy: a new approach to the treatment of choroidal neovascularization secondary to age-related macular degeneration

Visual loss as a result of choroidal neovascularization secondary to age-related macular degeneration continues to be a major challenge for all ophthalmologists. Photodynamic therapy represents an exciting and novel technique that uses light-activated drugs and nonthermal light to achieve the selective destruction of choroidal neovascularization with minimal effects on the surrounding normal tissues. In Phase I-II clinical trials of photodynamic therapy with both benzoporphyrin derivative and tin ethyl etiopurpurin, closure of choroidal neovascularization was seen 24 hours after the treatment. However, recurrence of choroidal neovascularization can occur 2 to 3 months after treatment. Double-blind, multicenter, randomized Phase III clinical trials with benzoporphyrin derivative and tin ethyl etiopurpurin are currently underway.

Laser and multipolar electrocoagulation ablation of early Barrett's adenocarcinoma: long-term follow-up

BACKGROUND

Endoscopic ablation of Barrett's esophagus, including associated dysplasia and adenocarcinoma, can be achieved by various techniques, but few long-term results are available. The aim of our study was ablation of intramucosal adenocarcinoma with a combination of Nd:YAG laser plus multipolar electrocoagulation.

METHODS

Patients with documented Barrett's esophagus and adenocarcinoma who either had refused surgery or were poor candidates for surgery because of high risk were offered endoscopic therapy. Patients underwent therapy with Nd:YAG laser and multipolar electrocoagulation. They were treated with omeprazole (20 mg twice daily) as maintenance therapy.

RESULTS

Six patients were enrolled in the study over a 7-year period. All were men with a mean age of 78.2 years. The mean length of Barrett's esophagus was 6.0 cm (range, 3 to 10 cm). Seventeen Nd:YAG laser (mean, 2.8/patient) and 20 multipolar electrocoagulation (mean, 3.3/patient) sessions were used during the study period. All patients had a complete initial response to therapy. One patient on chronic immunosuppressive medications had recurrence of the tumor after an initial complete response (36-month follow-up). Two patients have no evidence of Barrett's esophagus, and 3 patients have residual intestinal metaplasia on biopsy of an irregular appearing "neo" Z-line. Mean follow-up in this group is 3.4 years (range, 9 to 86 months).

CONCLUSIONS

Laser photocoagulation and multipolar electrocoagulation can be successfully and safely used to ablate intramucosal adenocarcinoma in the setting of Barrett's esophagus. Patients remain functional with normal swallowing.

Prevalence and location of nodal metastases in distal esophageal adenocarcinoma confined to the wall: implications for therapy

OBJECTIVE

The purpose of this study was to characterize the prevalence and location of regional lymph node metastases in adenocarcinoma confined to the esophagal wall, to determine the extent of dissection required, and to investigate the applicability of nonoperative therapy.

METHODS

Histologic evaluation of the resected specimens after en bloc esophagogastrectomy with mediastinal and abdominal lymphadenectomy was performed on 37 patients with adenocarcinoma confined to the esophageal wall. Follow-up was complete in all patients (median 24 months).

RESULTS

Fifteen patients (41%) had intramucosal tumors. Twelve (32%) had submucosal tumors and 10 (27%) had muscular invasion. The prevalence of regional lymph node metastases (15/37 patients, 41%) increased progressively with depth of tumor invasion, with involved nodes identified in 80% of patients with muscular invasion. Lymph node metastases were also more common at distant node stations in intramuscular tumors (5/10, 50%). Actuarial survival for the entire group was 63% at 5 years. Recurrence was identified in 6 of the 37 patients (16%), with the risk of recurrence correlating with tumor depth.

CONCLUSIONS

Tumor depth is a strong predictor of the probabilities of regional lymph node metastases, the likelihood of involvement of distant node groups, and the risk of recurrence. Patients with invasion of the muscular wall are at particularly high risk. En bloc esophagectomy with mediastinal and abdominal lymphadenectomy has the highest likelihood of achieving an R0 resection. The long-term survival and low recurrence rate achieved with an en bloc esophagectomy emphasizes the importance of an aggressive lymph node dissection to remove all potentially involved nodes.

What does photodynamic therapy have to offer radiation oncologists (or their cancer patients)?

Major advances have recently been made in photodynamic therapy (PDT) for clinical application, including the development of more powerful photosensitizers and light sources and suitable light applicators. PDT is emerging as an attractive new form of cancer therapy, suitable for treating superficial lesions (less than 1 cm in depth) and carcinoma in situ, or as an adjuvant to surgery for more bulky disease. PDT is therefore complementary to radiotherapy which is better suited to treating larger tumours. There are some qualitative similarities between light distribution in tissue during superficial illumination and ionizing radiation dose distributions during external beam irradiation, or between interstitial PDT and brachytherapy, although the geometric scale is very different (visible light penetrates a maximum of 5-10 mm in tissue). The contribution of scattered light to tissue irradiance is much greater than for ionizing radiation and in situ light dosimetry is very important (although rather complicated) to ensure adequate illumination without over-treating. Dosimetry and treatment planning are highly advanced for ionizing radiation and are routine in all radiotherapy departments. Proper in situ light dosimetry and dose distribution calculation for PDT is in its infancy. Physicists have an important role to play in the further optimization of clinical PDT and much of the infrastructure and expertise present in the radiotherapy department is ideally suited to accommodate PDT. In this review, parallels and contrasts are made between PDT and ionizing radiation for both mechanistic and dosimetric aspects of the therapies. A summary of the most interesting clinical applications is also given.

Cell cycle phase influences tumour cell sensitivity to aminolaevulinic acid-induced photodynamic therapy in vitro

Photodynamic therapy (PDT) is a form of cancer treatment based on the destruction of cells by the interaction of light, oxygen and a photosensitizer. Aminolaevulinic acid (ALA) is the prodrug of the photosensitizer protoporphyrin IX (PpIX). ALA-induced PDT depends on the rate of cellular synthesis of PpIX, which may vary with cell cycle phase. This study has investigated the relationship between cell cycle phase, PpIX generation and phototoxicity in synchronized and unsynchronized bladder cancer cells (HT1197). In unsynchronized cells, relative PpIX fluorescence values (arbitrary units) were significantly different between cell cycle phases after a 1-h ALA incubation (G1 24.8 +/- 0.7; S-phase, 32.7 +/- 0.8, P < 0.05; G2 35.4 +/- 0.8, P < 0.05). In synchronized cells after a 1-h ALA incubation, cells in G1 produced less PpIX than those in S-phase or G2 [6.65 +/- 1.1 ng per 10(5) cells compared with 15.5 +/- 2.1 (P < 0.05), and 8.1 +/- 1.8 ng per 10(5) cells (not significant) respectively] and were significantly less sensitive to ALA-induced PDT (% survival, G1 76.2 +/- 8.3; S-phase 49.7 +/- 4.6, P < 0.05; G2 44.2 +/- 2.4, P < 0.05). This differential response in tumour cells may have implications for clinical PDT, resulting in treatment resistance and possible failure in complete tumour response.

Clinical photodynamic therapy for superficial cancer in the oesophagus and the bronchi: 514 nm compared with 630 nm light irradiation after sensitization with Photofrin II

Photodynamic therapy (PDT) for cancer in the oesophagus and bronchi with red (630 nm) light may occasionally lead to wall perforation and fistula. Therefore, we investigated the clinical use of a less penetrating wavelength (514 nm) for the curative treatment of nine superficial carcinomas in the oesophagus and bronchi after photosensitization with Photofrin II. Tumours without infiltration beyond the submucosa in the oesophagus and beyond the lamina propria in the bronchi were considered as superficial cancers. The outcome and complications were compared with those of 13 superficial cancers treated with PDT and 630 nm light. In addition, we evaluated histologically the extent of the long-term tissue damage and scarring following treatment of six oesophageal cancers with either green or red light. At first endoscopic control, 7-10 days after PDT, tissue necrosis simply matched the illuminated area, without evidence of selective tumour damage. Six of nine tumours treated with 514 nm light had a complete response compared with nine of 13 after 630 nm irradiation. No perforation or fistula occurred in either treatment group. However, severe chest pain and fever with or without pleural effusion, consistent with occult perforation, were observed in three patients after 630 nm illumination in the oesophagus. Histologically, fibrous scarring in the three distinct sites treated with green light was limited to the superficial layers of the oesophagus. After red light treatment, transmural fibrosis with marked thinning of the oesophageal wall was evident in two of the three specimens available for inspection. These results indicate that PDT with 514 nm light has the potential to cure superficial cancer in the oesophagus and bronchi with essentially the same probability of success as red light. In the oesophagus, green light prevents deep tissue damage, thus reducing the risk of perforation.

Photodynamic ablation of high-grade dysplasia and early cancer in Barrett's esophagus by means of 5-aminolevulinic acid

BACKGROUND & AIMS

The first therapeutic experiences with the conventional photosensitizer dihematoporphyrinester in the treatment of Barrett's esophagus show the curative potential of photodynamic therapy (PDT). The aim of this study was to test 5-aminolevulinic acid (5-ALA)-induced protoporphyrin IX, a photosensitizer with a high mucosa specificity without phototoxic side effects on the skin, as a new form of PDT.

METHODS

Thirty-two patients (mean age, 68.5 years) with histologically proven high-grade dysplasia (n = 10) and mucosal cancer (n = 22) in Barrett's esophagus were treated. Four to 6 hours after oral ingestion of 5-ALA (dose, 60 mg/kg body wt), irradiation was conducted with a dye laser system (635 nm) with a light dose of 150 J/cm2. The patients received 20-80 mg omeprazole daily after PDT.

RESULTS

High-grade dysplasia was eradicated in all patients (10 of 10), and mucosal cancer was eliminated in 17 of 22 patients (77%) at a mean follow-up of 9.9 months (range, 1-30 months). All tumors < or = 2 mm in thickness were completely ablated (17 of 17). The method-related mortality and morbidity was 0%.

CONCLUSIONS

Severe dysplasia and thin (< or = 2 mm) mucosal cancer of Barrett's esophagus can be completely ablated. PDT might offer a minimally invasive treatment modality as an alternative to esophagectomy.

Photodynamic therapy of nonresectable cholangiocarcinoma

BACKGROUND & AIMS

Successful treatment in nonresectable Bismuth type III and IV cholangiocarcinoma is seldom achieved. The aim of this study was to evaluate the effect of photodynamic therapy on cholestasis, quality of life, and survival in these patients.

METHODS

Nine patients with advanced nonresectable cholangiocarcinomas Bismuth type III and IV, who showed no sufficient drainage (bilirubin decrease <50%) after endoscopic stent insertion, underwent photodynamic therapy. Two days after intravenous application of a hematoporphyrin derivate, intraluminal photoactivation was performed cholangioscopically. Serum bilirubin, quality of life, and survival time were assessed in two monthly intervals after photodynamic therapy.

RESULTS

After photodynamic therapy, bilirubin serum levels declined from 318 +/- 72 to 103 +/- 35 micromol/L (P = 0.0039) with no significant increase during the two monthly follow-ups. Quality of life indices improved dramatically and remained stable (e.g., Karnofsky index from 32.2% +/- 8.13% to 68.9% +/- 6.1%; P = 0.0078). Thirty-day mortality was 0%, and median survival time was 439 days.

CONCLUSIONS

This study provides clear evidence that photodynamic therapy is effective in restoring biliary drainage and improving quality of life in patients with nonresectable disseminated cholangiocarcinomas Bismuth type III and IV. Compared with published data, survival time seems to be prolonged.

Endoscopic therapy of esophageal cancer

In the management of esophageal cancer, endoscopy has evolved from a tool used to provide biopsy confirmation of suspected tumor to an integral part of the staging and ongoing treatment of patients. Endoscopic ultrasound is currently the most accurate means for T and N staging. Improved endoscopic techniques like dye staining and aggressive biopsy protocols can identify very early stage tumors in high-risk groups and allow curative surgery. Patients with early-stage tumors who are not surgical candidates can also be treated with endoscopic mucosectomy, photodynamic therapy, or Nd:YAG laser and still have a chance of long-term cure. Palliation of advanced tumors remains the major role of endoscopy in patients with esophageal cancer. A variety of techniques have proven effective over the years, including dilatation, laser, and rigid prostheses. Newer developments like bipolar probes, injection therapy, photodynamic therapy, and brachytherapy offer potential applications. The development and continuing improvements in both coated and uncoated expandable metal stents have been perhaps the greatest recent advance in endoscopic palliation of malignant dysphagia and esophagorespiratory fistulas. With the increasing array of endoscopic treatments and palliative techniques, emphasis must be placed on considering functional status; tumor characteristics like stage, location, and shape; patient wishes; and local expertise in tailoring treatment plans for each situation.

Management of dysplasia in the columnar-lined esophagus

The management of patients with high-grade dysplasia in Barrett's esophagus is complex and controversial with regard to electing continued endoscopic biopsy surveillance until an early adenocarcinoma is detected or proceeding with partial esophagogastrectomy. Clinical recommendations to patients for either option should be individualized and based on several parameters reflecting patient and clinician factors. Available data on interpretational variation in the diagnosis of dysplasia; limitation of diagnostic errors with the use of a rigorous, systematic endoscopic biopsy protocol; new information on the apparent benign natural history of high-grade dysplasia in some patients; and the morbidity and mortality of esophageal resection all suggest that recommendation for continued endoscopic biopsy surveillance is an appropriate clinical practice in selected patients. Ongoing research investigations on high-grade dysplasia in Barrett's esophagus aim to reduce the potential for diagnostic errors, simplify cancer surveillance, and develop therapeutic interventions that are safer than but as effective as surgery.

Ablative therapies for the columnar-lined esophagus

Endoscopic ablative therapy could reduce the risk for the development of adenocarcinoma in patients with Barrett's esophagus. Combination therapy, which includes pharmacologic or surgical acid control plus endoscopic mucosal ablation, can reverse Barrett's esophagus that has not been accomplished with prior medical or surgical therapy. Pharmacologic esophageal acid control often takes higher than usual doses of proton pump inhibitor therapy. The preliminary results of endoscopic ablation techniques, including laser, photodynamic therapy, and multipolar electrocoagulation, are reviewed. The goal of ablative therapy is to eliminate all intestinal metaplasia and therefore the risk for the development of adenocarcincoma. Endoscopic ablative therapies need to be validated with larger and longer term trials. Better criteria to estimate the risk for the development of adenocarcinoma are needed to select appropriate candidates for combination therapy.

Side effects and photosensitization of human tissues after aminolevulinic acid

Aminolevulinic acid (ALA) is being used as a "prodrug" for photodynamic therapy. The side effects of ALA have been only anecdotally reported and these effects as well as pharmacokinetics of the photosensitizing end product of ALA, protoporphyrin IX (PpIX), in patients undergoing operation are unknown. This study systematically determines the side effects of ALA and pharmacokinetics of PpIX in patients undergoing abdominal surgery. Patients were given 30 or 60 mg/kg ALA preoperatively, kept in subdued light for 48 hr, and monitored clinically and with laboratory tests for 5 to 7 days and for at least 2 months thereafter. Periodic plasma samples and tissue biopsies were analyzed for PpIX concentrations using a photodiode array system. No patient developed symptoms of porphyria other than nausea and vomiting, which occurred in 20%. Nearly one-quarter of patients developed transient abnormal liver functions. No patient developed cutaneous phototoxicity, abnormal neurologic function, or unexpected postoperative laboratory tests. The times of peak plasma, skin, skeletal muscle, omental, mucosal, muscularis mucosal, and tumor concentrations of PpIX varied among patients. In general, PpIX concentrations were significantly greater with the higher dose of ALA. Tumor PpIX concentrations were significantly greater than in other tissues except liver. In conclusion, ALA, up to 60 mg/kg, is associated with minimal side effects in patients undergoing operation. Actual tissue concentrations of PpIX suggest that endogenous photosensitization using systemically administered ALA is a mode of PDT feasible for treatment of adenocarcinomas of the gastrointestinal tract in humans.

Photodynamic therapy of endobronchial and esophageal tumors: an overview

From 1982 to March 1996 we treated 211 patients with endobronchial tumors and 106 patients with esophageal tumors using photodynamic therapy (PDT) in an ongoing study of the efficacy of PDT. This paper is an overview of our results and the evolvement of our current techniques for using PDT.

Photodynamic therapy for esophageal malignancy: a prospective twelve-year study

BACKGROUND

We wanted to determine factors affecting survival rates of benefits to, and complications in patients with esophageal cancer treated with photodynamic therapy.

METHODS

From 1982 to January 1994, we used photodynamic therapy to treat 77 patients with esophageal carcinoma and evaluated survival to July 1994. All patients had failed, refused, or were ineligible for surgical intervention, ionizing radiation therapy, or chemotherapy.

RESULTS

The only significant variable affecting survival was clinical stage. Median survival after photodynamic therapy was as follows: all patients, 6.3 months (mean survival, 9.2 months); stage I, not reached; stage II, 12 months; stage III, 6.2 months; and stage IV, 3.5 months. For stages III and IV, a Karnofsky performance status of 70 or higher had a significant effect. For stage III, the median survival was 6.3 months when the Karnofsky performance status was equal to or greater than 70 and 3.5 months when it was less than 70. For stage IV, the median survival was 5.5 months when the Karnofsky performance status was equal to or greater than 70 and 2.5 months when it was lower than 70. Seven stage I patients with no treatment prior to photodynamic therapy had an estimated 5-year survival rate of 62%. Three patients with stage I invasive adenocarcinoma and Barrett's mucosa diagnosed when they underwent endoscopy for dysphagia were alive with no evidence of disease 17, 44, and 59 months after photodynamic therapy.

CONCLUSIONS

Photodynamic therapy for esophageal carcinoma caused minimal complications and no procedure-related deaths. Photodynamic therapy can be considered an alternative treatment for patients with Barrett's esophagus with severe dysplasia or patients with stage I carcinoma who are under consideration for operation but are high surgical risks. The length of palliation for patients having "noncurative" treatment was equal to or better than that reported historically for most other treatment regimens.

Photodynamic therapy for cancer of the upper aerodigestive tract using tetra(m-hydroxyphenyl)chlorin

A major step in the development of photodynamic therapy (PDT) is the clinical optimization and evaluation of new photosensitizers (PS). Ideally, new compounds should be more effective and/or induce fewer side effects than the first generation PS such as hematoporphyrin derivative and Photofrin. We report the results of our study of PDT applied in the human upper aerodigestive tract, using tetra(m-hydroxyphenyl)chlorin (mTHPC) as the photosensitizing drug. Twenty-seven patients with early (i.e., in situ or microinvasive) squamous cell carcinomas and 4 patients with T1 or T2 cancers were studied. In most cases, illumination of the tumor was performed 4 days after i.v. injection of 0.15 mg/kg of mTHPC using 652 or 514 nm laser light. Of the 36 early tumors evaluated 30 (83%) showed no recurrence after a mean disease-free follow-up of 15.3 months (3-35 months). Of the T1 and T2 cancers, only one achieved a complete response. Major complications, all following red light illuminations, included 1 bronchial stenosis, 1 esophagotracheal fistula, and 2 probable occult perforations of the esophagus. PDT in the esophagus with green light renders such perforations essentially impossible, without, however, reducing the efficacy of the treatment. Skin photosensitization, never observed later than the first week after injection, was seen in 12 patients. In conclusion, photodynamic therapy with mTHPC is a safe and effective technique for the treatment of early carcinomas of the upper aerodigestive tract. Its efficacy is much lower for more advanced cancers.