Stage T1A carcinoma of prostate

Active surveillance: the Canadian experience with an "inclusive approach"

Active surveillance has evolved to become a standard of care for favorable-risk prostate cancer. This is a summary of the rationale, method, and results of active surveillance beginning in 1995 with the first prospective trial of this approach. This was a prospective, single-arm cohort study. Patients were managed with an initial expectant approach. Definitive intervention was offered to those patients with a prostate-specific antigen (PSA) doubling time of less than 3 years, Gleason score progression (to 4+3 or greater), or unequivocal clinical progression. Survival analysis and Cox proportional hazard model were applied to the data. Since November 1995, 450 patients have been managed with active surveillance. The cohort included men under 70 with favorable-risk disease and men of age more than 70 with favorable- or intermediate-risk cancer (Gleason score 3+4 or PSA 10-15). Median follow-up is 6.8 years (range 1-16 years). Overall survival is 78.6%. Ten-year prostate cancer actuarial survival is 97.2%. Five of 450 patients (1.1%) have died of prostate cancer. Thirty percent of patients have been reclassified as higher-risk patients and offered definitive therapy. The commonest indication for treatment was a PSA doubling time less than 3 years (48%) or Gleason upgrading (26%). Of 117 patients treated radically, the PSA failure rate was 50%. This represents 13% of the total cohort. Most PSA failures occurred early; at 2 years, 44% of the treated patients had PSA failure. The hazard ratio for non-prostate cancer mortality to prostate cancer mortality was 18.6 at 10 years. In conclusion, we observed a very low rate of prostate cancer mortality in an intermediate time frame. Among the one-third of patients who were reclassified as higher risk and retreated, PSA failure was relatively common. However, other-cause mortality accounted for almost all of the deaths. Further studies are warranted to improve the identification of patients who harbor more aggressive disease in spite of favorable clinical parameters at diagnosis [reproduced from Klotz (1) with permission from Wolters Kluwer Health].

Lymphangiogenesis in cancers: A therapy target

Tumor metastasis is a major cause of death among cancer patients. The lymphatic vasculature is an important route for the metastatic spread of cancer. Recent research has indicated that vascular endothelial growth factor C (VEGF-C), VEGF-D and VEGF receptor-3 (VEGFR-3) are closely related to tumor-induced lymphangiogenesis, tumor metastasis and prognosis. Numerous studies demonstrate that the VEGF-C/VEGF-D/VEGFR-3 signaling axis plays a leading role in the regulation of tumor lymphangiogenesis and is related to tumor metastasis and prognosis. It has been confirmed that inhibition of the VEGF-C/VEGF-D/VEGFR-3 signaling axis can exert anti-lymphangiogenic effect and thereby prevent tumor metastasis in animal models. In this paper we review the molecular biology of lymphangiogenesis, its relationship with cancer metastasis, and the clinical implications of inhibition of lymphangiogenesis.

Tumor lymphatics

In this article we survey more than three centuries of observation and research into tumor-associated lymphatic vessels, and their role in the metastatic spread of cancer. This historical overview documents how questions regarding tumor lymphatics have been central to concepts about the process of metastasis, and how this has subsequently influenced the clinical treatment of cancer. In turn, we show how analysis of the efficacy of these treatments has challenged long-standing notions regarding the tumor lymphatics. Starting with the discovery of VEGFR-3 and its ligands VEGF-C and VEGF-D, we also review how the rapid developments over the last 15 years in the molecular analysis of the lymphatic system and in particular lymphangiogenesis have contributed to this debate. Finally we speculate on how apparently paradoxical bodies of evidence regarding the role of tumor lymphatics in determining patterns of metastatic spread might be reconciled.

Transition zone and anterior stromal prostate cancers: zone of origin and intraprostatic patterns of spread at histopathology

BACKGROUND

To describe the precise location of transition zone (TZ) and anterior fibromuscular stroma (AFMS) prostate cancers (TZ/AFMS) within histological zones at various stages of development and to demonstrate their pattern of intraprostatic spread from their site of origin.

METHODS

Anterior TZ/AFMS cancers excluding the anterolateral part of peripheral zone, were identified from radical prostatectomy specimens. Morphometric histopathological study included largest surface area, volume and spatial distribution.

RESULTS

Out of 91 TZ/AFMS cancers, 79 were <4 cm3 and 69 <2 cm3. Fifty percent and 70% of cancers <4 cm3 were located in the anterior third and inferior half of TZ and/or AFMS, respectively. Cancers <2 cm3 could be classified into three types according to their location related to histologic zone boundaries: TZ type 1 (40%) for cancers confined to one TZ lobe; TZ type 2 (35%) for cancers most represented in one TZ lobe but crossing its anterior boundary; type AFMS (25%) for cancers confined to AFMS. These results form the rationale for the hypothesis that AFMS cancers originate from anterior and medial TZ and due to benign prostatic hypertrophy they become excluded from TZ, anteriorly into AFMS. TZ anterior limit would then act as a barrier to their posterior extension.

CONCLUSIONS

TZ/AFMS cancers contours and locations are predictable and conform to histological zones boundaries. Knowledge of these cancer origin and pattern of spread in TZ and AFMS are of importance for imaging diagnosis, guidance for biopsy and focal therapy.

Predictive Factors for Progression in Patients with Clinical Stage T1a Prostate Cancer in the PSA Era

OBJECTIVE

In the literature, most data regarding the outcome of patients with clinical stage T1a prostate cancer were established before the prostate-specific antigen (PSA) era. The aim of our study was to determine the predictive factors of progression in patients with T1a prostate cancer diagnosed in the PSA era.

METHODS

Consecutive patients (n=144) with newly diagnosed T1a prostate cancer (tumor involving < or =5% of the resected prostatic tissue) were included. None of them was treated before evidence of tumor progression confirmed by prostate needle biopsies. The associations between tumor characteristics and time to cancer progression were assessed using Cox regression analysis.

RESULTS

With a mean follow-up of 5.1 yr, 30 patients (21%) experienced cancer progression. Five adverse parameters were significantly associated with cancer progression: preoperative PSA> or =10 ng/ml, postoperative PSA> or =2 ng/ml, prostate weight > or =60 g, weight of resected tissue > or =40 g, and Gleason score> or =6. The 5-yr progression rate was 12% if fewer than two of these parameters were present, whereas it was 47% if two or more parameters were present (p<0.001).

CONCLUSION

In the PSA era the risk of progression associated with T1a prostate cancer can be predicted using five criteria, and two groups of patients can be defined. The patients at low risk of progression may be good candidates for surveillance. In those with a high risk of progression, a more aggressive treatment should be discussed.

Subclassification of clinical stage T1 prostate cancer: impact on biochemical recurrence following radical prostatectomy

PURPOSE

We investigated biochemical outcomes following radical prostatectomy across subclassifications of clinical stage T1 prostate cancer.

MATERIAL AND METHODS

Of 8,658 men who underwent radical prostatectomy for clinical stage T1 prostate cancer 85, 156 and 8,417 had clinical stage T1a, T1b and T1c disease, respectively. Age, race, prostate specific antigen, year of surgery and preoperative Gleason scores were compared across clinical stage T1 subcategories. Time to prostate specific antigen recurrence was compared among groups using Kaplan-Meier and Cox hazards modeling.

RESULTS

Patients with clinical stage T1a prostate cancer had more favorable postoperative pathological features, including lower prostatectomy Gleason scores (p <0.001), rates of extraprostatic extension (p <0.001), lymph node invasion (p <0.001) and positive surgical margins (p = 0.006). Patients with T1a cancer also showed significantly lower rates of biochemical recurrence on Kaplan-Meier analysis than men with T1b and T1c disease (log rank 0.006). Cox regression analysis adjusted for known predictors of biochemical recurrence demonstrated that clinical tumor stage in the subgroup of patients with T1 disease was not an independent predictor of biochemical recurrence (p = 0.321).

CONCLUSIONS

Men with clinical stage T1a prostate cancer who undergo radical prostatectomy have significantly lower biochemical recurrence rates than men with stage T1b or T1c disease. However, subclassification of tumors in this group of patients was not an independent prognostic factor for biochemical recurrence after accounting for preoperative variables, including prostate specific antigen and Gleason score.

Diagnosis of prostate cancer

The contemporary challenge of prostate cancer diagnosis has been changed in the past decade from the endeavor to increase detection to that of detecting only those tumors that are clinically significant. Better interpretation of the role of prostate-specific antigen (PSA) and its kinetics as a diagnostic tool, the adoption of extended prostate biopsy schemes, and perhaps implementation of new transrectal ultrasound (TRUS) technologies promote the achievement of this clinical mission. This chapter reviews these issues as well as the change in practice of patient preparation for TRUS-biopsy and analgesia during it, the role of repeat and saturation prostate biopsies, and the interpretation of an incidental prostate cancer finding. Currently, the lifetime risk of a diagnosis of prostate cancer for North American men is 16%, compared to the lifetime risk of death from prostate cancer, which is 3% (Carter 2004). The advent of prostate-specific antigen (PSA) screening and transrectal ultrasonography (TRUS) has significantly impacted the detection of prostate cancer over the last 20 years. The mean age at diagnosis has decreased (Hankey et al. 1999; Stamey et al. 2004) and the most common stage at diagnosis is now localized disease (Newcomer et al. 1997; Stamey et al. 2004). The goal of prostate cancer screening is to detect only those men at risk for death from the disease at an early curable phase. The ambiguous natural history of this most common malignancy in men, being latent with questionable life-threatening potential in a large number of cases on the one hand, with only a relatively small number (though not negligible) of highly malignant cases on the other, propels many doubts about whether this is possible. This was famously phrased more than 20 years ago by Whitmore who asked: "Is cure possible for those in whom it is necessary; and is it necessary for those in whom it is possible?" This is probably even more relevant nowadays. During the past decade two factors influenced significantly the increased detection rate of prostate cancer in general and that of clinically insignificant prostate cancers in particular: the widespread use of serum PSA as a screening tool to a large extent and to a lesser though significant extent the application of extended multiple core biopsy schemes (Master et al. 2005). In fact, 75% of men in the United States aged 50 years and older have been screened with the PSA test (Sirovich et al. 2003). Outside of the screening context, which is dealt with in depth in Chap. 5, clinical suspicion of prostate cancer is raised usually by abnormal digital rectal examination (DRE) and/or by abnormal levels of serum PSA. Final diagnosis is achieved only based on positive prostate biopsies.

Tumor-induced lymphangiogenesis: a target for cancer therapy?

Recent advances in understanding the biology of lymphangiogenesis, the new growth of lymphatic vessels, have cast new light on the molecular basis of metastasis to regional lymph nodes. The receptor tyrosine kinase VEGFR-3 is virtually exclusively expressed on lymphatic but not blood endothelium in the adult, and activation of VEGFR-3 by its ligands VEGF-C and VEGF-D is sufficient to induce lymphangiogenesis. Correlative studies with human tumors and functional studies using animal tumor models show that increased levels of VEGF-C or VEGF-D in tumors lead to enhanced numbers of lymphatic vessels in the vicinity of tumors, which in turn promotes metastasis to regional lymph nodes by providing a greater number of entry sites into the lymphatic system for invading tumor cells. These findings have prompted studies to investigate whether inhibitors of VEGFR-3 activation might represent novel therapeutic agents for the suppression of metastasis. However, a number of points regarding the therapeutic potential of anti-lymphangiogenic treatments in the context of cancer remain to be addressed. The spectrum and relative importance of molecules that induce lymphangiogenesis and the regulation of their expression during tumor progression, the reversibility of tumor-induced lymphangiogenesis, and possible side-effects of anti-lymphangiogenesis-based therapies all need to be investigated. Most importantly, the extent to which lymph node metastases contribute to the formation of metastases in other organs remains to be elucidated. These aspects are the focus of this review, and their investigation should serve as a roadmap to possible translational application.

Cáncer de próstata incidental: T1a-T1b. Nuestra experiencia tras observación/intervención radical y revisión de la literatura

OBJECTIVES

To analyse the progress of T1a and T1b prostate cancer diagnosed in our hospital.

MATERIAL AND METHODS

Retrospective study of 40 patients in T1a-T1b clinical stage diagnosed with prostate adenocarcinoma in our hospital, from 1986 to 1999. A restaging biopsy was performed on the 16 T1a patients after initial diagnosis and control. A radical prostatectomy was performed on the 24 T1b patients. They were all monitored every six months with rectal exam and PSA. We analysed biological and/or clinical progression, time to progression, mortality caused by the tumour and survival.

RESULTS

None of the 16 patients with T1a clinical stage presented tumour progression, with a median follow-up of 90 months. 12,5% of the 24 T1b cases presented tumour progression, with a median follow-up of 70 months. Cancer-specific mortality was one patient (4,16 %) in the T1b group.

CONCLUSIONS

Observation and follow-up with PSA and rectal exam appears to be a good option for T1a clinical stage, given the good prognosis. Our results show that patients with T1a clinical stage and good prognostic factors could be at a similar risk of suffering from a new prostate cancer as the normal population, although prospective studies are required to validate these results. T1b cases require active treatment and closer monitoring.

MAZ51, an indolinone that inhibits endothelial cell and tumor cell growthin vitro, suppresses tumor growthin vivo

We have recently described MAZ51, an indolinone that blocks the ligand-induced autophosphorylation of VEGFR-3, a receptor tyrosine kinase that plays a central role in the regulation of lymphangiogenesis. Here we show that MAZ51 is able to block the proliferation of VEGFR-3-expressing human endothelial cells and is less potently able to induce their apoptosis. MAZ51 also inhibits the proliferation and induces the apoptosis of a variety of non-VEGFR-3-expressing tumor cell lines. These data suggest that MAZ51 blocks the activity of tyrosine kinases in addition to VEGFR-3. In vivo, MAZ51 significantly inhibits the growth of rat mammary carcinomas. These data establish MAZ51 as a compound with antitumor properties that inhibits tumor growth directly and also indirectly by interfering with tumor-host interactions.

Did the rate of incidental prostate cancer change in the era of PSA testing? A retrospective study of 1127 patients

OBJECTIVES

To evaluate, in a retrospective study, the impact of routine prostate-specific antigen (PSA) testing on the rate of incidental prostate cancer in patients undergoing surgery for obstructive symptoms caused by presumed benign prostatic enlargement (BPE) and to investigate the indication of a routine biopsy before alternative treatment procedures for BPE. In the pre-PSA era, the diagnosis of incidental carcinoma was exclusively based on normal digital rectal examination (DRE) findings.

METHODS

Since January 1993, 2422 operations (2283 transurethral resection of the prostate, 139 retropubic adenoma enucleations) for BPE were performed at our institution. The preoperative DRE findings and PSA level were evaluated, and patients with any suspicion for cancer were excluded. The pathologic reports of all patients were reviewed. A diagnosis of incidental carcinoma of the prostate required histologic evidence of cancer and negative DRE findings and a PSA level within age-specific reference ranges preoperatively.

RESULTS

Of 2422 patients, 1127 (46.5%) had both negative DRE findings and an age-specific PSA level and were evaluated for our study. Overall, prostate cancer was diagnosed by surgery in 314 (13%) of 2422 patients. The rate of incidental prostate cancer in patients with both negative age-specific PSA levels and negative DRE findings was 6.4% (72 of 1127).

CONCLUSIONS

In our series, the likelihood of detecting incidental prostate cancer by surgery was 6.4%. In the PSA era, the rate of incidental prostate cancer has been decreased by more than 50%. Today, the low rate of incidental carcinoma does not warrant routine histologic evaluation of the prostate if PSA testing and DRE are negative when alternative treatment modalities without tissue sampling are offered for the treatment of BPE.

Characterization of indolinones which preferentially inhibit VEGF-C- and VEGF-D-induced activation of VEGFR-3 rather than VEGFR-2

VEGF-C and VEGF-D are lymphangiogenic factors that bind to and activate VEGFR-3, a fms-like tyrosine kinase receptor whose expression is limited almost exclusively to lymphatic endothelium in the adult. Processed forms of VEGF-C and VEGF-D can also activate VEGFR-2, a key player in the regulation of angiogenesis. There is increasing evidence to show that these receptor-ligand interactions play a pivotal role in a number of pathological situations. Inhibition of receptor activation by VEGF-C and VEGF-D could therefore be pharmaceutically useful. Furthermore, to understand the different roles of VEGF-C, VEGF-D, VEGFR-2 and VEGFR-3 in pathological situations it will be necessary to dissect the complex interactions of these ligands and their receptors. To facilitate such studies we cloned, sequenced and characterized the expression of rat VEGF-C and VEGF-D. We showed that Cys152-->Ser mutants of processed rat VEGF-C can activate VEGFR-3 but not VEGFR-2, while the corresponding mutation in rat VEGF-D inhibits its ability to activate both VEGFR-2 and VEGFR-3. We also synthesized and characterized indolinones that differentially block VEGF-C- and VEGF-D-induced VEGFR-3 kinase activity compared to that of VEGFR-2. These tools should be useful in analysing the different activities and roles of VEGF-C, VEGF-D and their ligands, and in blocking VEGFR-3-mediated lymphangiogenesis.

Treatment of prostate cancer: watchful waiting, radical prostatectomy, and cryoablation

Current advances in diagnostic modalities and screening has lead to diagnosis of prostate cancer at an earlier stage (the so-called "stage shift" phenomenon), making primary treatments of localized disease of extreme importance in management. Therapeutic modalities include conservative management, radical prostatectomy, external beam radiotherapy, and newer techniques such as cryoablation surgery and brachytherapy. This review will focus on the non-radiation, non-hormonal primary treatment of localized prostate cancer and discuss the popularity and success of "watchful waiting," radical surgery, and cryoablation along with their advantages and disadvantages. These treatments will be compared to the qualities of an ideal treatment, which include cost effectiveness, efficacy, convenience of administration, tolerance by patients, low morbidity and mortality, and minimal impact on quality of life.

The prognosis of stage A patients treated with the antiandrogen chlormadinone acetate

To determine the efficacy of the antiandrogen chlormadinone acetate as a treatment option for stage A prostate cancer, a retrospective analysis of 111 patients who received chlormadinone acetate was done. Of 55 stage A1 patients, progression was seen in one patient (1.8%) 8 years after the diagnosis. Six out of 56 stage A2 patients (10.7%) showed disease progression at 1-7 years (mean 68 months) after the diagnosis. Progression rates associated with antiandrogen therapy for stage A1 and stage A2 patients were lower than those without treatment reported in the literature. It could be assumed that antiandrogen treatment with chlormadinone acetate inhibited the progression.

Predictors of cancer progression in T1a prostate adenocarcinoma

BACKGROUND

The biologic behavior of T1a prostate adenocarcinoma is variable. A critical issue in the management of patients with T1a prostate adenocarcinoma is to distinguish those who will develop cancer progression from those who will not. Predictive factors that identify those at high risk of cancer progression are needed to stratify patients for treatment. In the current study the authors attempted to identify such predictors of cancer progression in a large series of untreated patients with lengthy follow-up.

METHODS

The authors studied 102 patients who were diagnosed with T1a prostate adenocarcinoma (incidental tumor involving < or = 5% of the resected prostatic tissue) at the time they underwent transurethral resection of the prostate (TURP) at the Mayo Clinic between 1960-1970. None of these patients were treated. Patient ages ranged from 48-91 years (mean +/- standard deviation, 69 +/- 7 years). The average weight of the resected prostate tissue was 24 +/- 18 g (range, 3-115 g; median, 18 g). Tumor volume was measured by the grid method. Cox proportional hazards models were used to identify factors associated with cancer progression. Survival curves were estimated using the Kaplan-Meier method.

RESULTS

Five-year and 10-year progression free survival rates were 93% and 87%, respectively. During the mean follow-up of 9.5 +/- 6.8 years (range, 0.3-31 years; median, 9.0 years), 14 patients developed clinical cancer progression, including 5 patients with systemic progression (1 with distant metastases and 4 who died of prostate adenocarcinoma). The interval from diagnosis to clinical cancer progression ranged from 1-23 years (mean, 7.3 years). The amount of resected prostate tissue (TURP weight) was associated with progression (P = 0.04). Patients with a TURP weight > or = 30 g had 100% progression free survival at 10 years compared with a progression free survival rate of 73% in patients with a TURP weight < 12 g. Gleason score, tumor volume, number of chips involved by tumor, number of tumor foci, and the presence of high grade prostatic intraepithelial neoplasia were not significant in predicting cancer progression. There was a trend toward a worse prognosis with the increasing number of chips involved by cancer (P = 0.16). Patients with < 3 chips involved by cancer had a 88% 10-year progression free survival rate compared with 73% in patients with > or = 3 chips involved by cancer.

CONCLUSIONS

The clinical course of T1a prostate adenocarcinoma is variable. If left untreated, a small but significant proportion of patients are at risk for disease progression and death. However, the current study found that patients with a TURP weight > or = 30 g have an excellent prognosis and can be managed conservatively.

Can screening for early-stage prostate cancer be rationalized?

Prostate-specific antigen (PSA)-based screening identifies prostate cancer at an earlier stage than digital rectal examination alone. The widespread use of PSA as a screening tool has led to a marked increase in the incidence of prostate cancer and an apparent shift toward the diagnosis of earlier stage disease. Proof that PSA-based screening results in a reduction in prostate cancer-related mortality is lacking currently. Therefore, insufficient data are available to determine whether a general screening strategy should be adopted for detecting early-stage prostate cancer. Patients at average risk should be educated about the value of PSA testing. Patient groups at high risk should be the targets of aggressive screening initiatives.