Cryosurgery for carcioma of prostate

Re-purposing cryoablation: a combinatorial 'therapy' for the destruction of tissue

It is now recognized that the tumor microenvironment creates a protective neo-tissue that isolates the tumor from the various defense strategies of the body. Evidence demonstrates that, with successive therapeutic attempts, cancer cells acquire resistance to individual treatment modalities. For example, exposure to cytotoxic drugs results in the survival of approximately 20-30% of the cancer cells as only dividing cells succumb to each toxic exposure. With follow-up treatments, each additional dose results in tumor-associated fibroblasts secreting surface-protective proteins, which enhance cancer cell resistance. Similar outcomes are reported following radiotherapy. These defensive strategies are indicative of evolved capabilities of cancer to assure successful tumor growth through well-established anti-tumor-protective adaptations. As such, successful cancer management requires the activation of multiple cellular 'kill switches' to prevent initiation of diverse protective adaptations. Thermal therapies are unique treatment modalities typically applied as monotherapies (without repetition) thereby denying cancer cells the opportunity to express defensive mutations. Further, the destructive mechanisms of action involved with cryoablation (CA) include both physical and molecular insults resulting in the disruption of multiple defensive strategies that are not cell cycle dependent and adds a damaging structural (physical) element. This review discusses the application and clinical outcomes of CA with an emphasis on the mechanisms of cell death induced by structural, metabolic, vascular and immune processes. The induction of diverse cell death cascades, resulting in the activation of apoptosis and necrosis, allows CA to be characterized as a combinatorial treatment modality. Our understanding of these mechanisms now supports adjunctive therapies that can augment cell death pathways.

Ten-year biochemical disease control for patients with prostate cancer treated with cryosurgery as primary therapy

OBJECTIVES

Prostate cryosurgery has been increasingly used for the management of localized prostate cancer since its introduction in a minimally invasive form in the early 1990s. We performed a retrospective study of the largest and most mature patient group treated with cryosurgery reported thus far.

METHODS

We retrospectively analyzed the data from 370 patients treated consecutively from 1991 to 1996 with a focus on the determination of biochemical disease-free survival for a group of patients with T1 to T3 prostate cancer who had undergone prostate cryosurgery as primary monotherapy. Only patients with no previous radiotherapy, hormonal therapy, or surgery were included.

RESULTS

The median follow-up was 12.55 years. Using a nadir plus 2 ng/dL definition, Kaplan-Meier analysis demonstrated a biochemical disease-free survival rate at 10 years of 80.56%, 74.16%, and 45.54% for low, moderate, and high-risk groups, respectively. The 10-year negative biopsy rate was 76.96%.

CONCLUSIONS

The results for this pilot group of patients who underwent percutaneous prostate cryosurgery monotherapy demonstrated biochemical disease-free survival rates that overlap with those of similar groups of patients treated under similar circumstances using other types of nonextirpative monotherapy.

Cryoablation for carcinoma of the prostate

Percutaneous transperineal cryoablation of the prostate is now available in the armamentarium for treatment of prostate cancer. Technical advances in real-time transrectal imaging of the prostate and improvements in cryosurgical equipment have brought this modality into the limelight of available prostate cancer management. Cryosurgery can be offered to many patients with prostate cancer. However, the main indications for its use include primary treatment for localized disease, salvage therapy after failure of traditional methods, and relief of local symptoms. A historical background, description of the technique, and clinical experience at several medical centers including the University of California San Diego, Allegheny General Hospital, University of Texas M.D. Anderson Cancer Center, and Crittenton Hospital, are presented.

Should cryosurgery be considered a therapeutic option in localized prostate cancer?

Cryosurgical ablation of the prostate currently is under investigation as a potential treatment for localized prostate cancer. Results to date indicate that the majority of patients have negative biopsies and a marked reduction in prostate-specific antigen levels following cryotherapy. This treatment, however, is associated with significant side effects, notably bladder outflow obstruction, impotence, and incontinence, and its long-term durability is still unknown.

Transrectal ultrasound-guided transperineal cryoablation in the treatment of prostate carcinoma: preliminary results

PURPOSE

We studied ultrasound-guided percutaneous cryoablation for treatment of prostate carcinoma.

MATERIALS AND METHODS

Our series includes 83 individuals who underwent transrectal ultrasound-guided transperineal percutaneous cryoablation of the prostate. Prostate specific antigen levels, biopsy results and complications were assessed at 3 months.

RESULTS

Of 61 biopsies 8 (13.1%) were positive for carcinoma (half showed stage D disease). Of patients with stages T1 to T3 cancer 92.6% were free of disease at 3 months. Prostate specific antigen levels were significantly decreased by an average of 1.90 ng./ml. (p < 0.05). Major complications were infrequent, including bladder perforation in 1 patient, urethral strictures in 3, bladder outlet obstruction in 2 and partial incontinence in 2. Impotence was frequent but transient.

CONCLUSIONS

Transrectal ultrasound-guided transperineal percutaneous cryoablation of the prostate produces few major complications and appears at 3 months to be effective in eradicating local prostate tumors. Longer followup is required to test the original hypothesis.

Cryotherapy

Since 1969 cryosurgical perineal destruction of the prostate has been developed at the University of Iowa for treatment of patients with prostatic cancer. The technique of this procedure has been the subject of previous reviews. This is a summary of our experience of patient survival and the effect on local prostatic cancer growth in those patients with various stages of the disease subjected to perineal cryosurgical destruction of their cancer. We also report briefly on our experience in the laboratory where the Dunning tumor model is used to study the effect of cryosurgery as well as combinations of immunological modifications.

Cryosurgery in prostatic cancer: elimination of local lesion

From 1969 through 1976, we performed cryosurgery in 229 cases of prostatic cancer. Most of these patients had bulky, locally extensive primary tumors, and one-half had disseminated disease. Through the open perineal approach, which gives exposure for an adequate freeze, cryosurgery has been well tolerated. The primary surgical goal has been to reduce or eliminate the local lesion to minimize subsequent cancer-related lower urinary tract problems and to cure those patients with truly localized disease. In every case cryosurgery produced dramatic shrinkage of the local lesion. After four to eight weeks a local recurrence was suspected in 13 per cent, and 41 per cent eventually had some evidence of a recurrent cancer nodule or persistent cancer in the bladder neck. In a series of statistical analyses we have related these recurrences to other clinical factors. Cryosurgery has been a safe, effective way to reduce or eliminate the primary prostatic cancer, even in patients with large local lesions.

Serum protein, enzyme and immunoglobulin responses following perineal cryosurgery for carcinoma of the prostate

Alterations in serum proteins, enzymes and immunoglobulins were analyzed sequentially in 40 patients undergoing perineal cryosurgery for carcinoma of the prostate. A search was made for evidence of a tumor marker and for augmented host response attributable to an immune mechanism. The data showed little evidence to support a systemic immune response. A reliable tumor marker could not be identified when cryosurgery was used alone.

Cryotherapy of prostate cancer

Cryosurgical destruction of primary adenocarcinoma of the prostate was performed via perineal route in 215 patients during a 12-year period. The average age of the patients was 66 years. The stage of the disease varied from stage B to D. In 74% of the patients, no clinical evidence of tumor was found in the prostatic fossa following cryosurgery. Few patients needed transurethral surgery and none needed repeated transurethral resections for obstructive symptoms. This experience suggests that local destruction of prostatic carcinoma can be achieved with little morbidity and mortality. Herein wer discuss the method of cryosurgery, stage and histology or tumor, survival, local recurrence, and complications.

Biopsy and clinical course after cryosurgery for prostatic cancer

Open perineal cryosurgical prostatectomy has been reported previously in 154 consecutive prostatic cancer patients at our center. In 37 of these patients post-cryosurgery biopsies of the prostate were obtained. In the present report we compare this tissue to the preoperative biopsies. The data suggest that well differentiated cancers are associated with advantageous survival in cryosurgery patients. Lymphoid and eosinophilic cell infiltrates may represent post-cryosurgical local immune responses, with improved survival. Estrogen therapy seems to suppress this local immune response. One month or more after cryosurgery cancer in the biopsy correlates with palpable local recurrence but prior to 1 month it does not correlate. Cryosurgery by the open perineal approach has been an effective method to eliminate the primary lesion in localized and extensive prostatic cancer.