With the widespread use of blood prostate-specific antigen (PSA) testing, the detection rate of prostate cancer and early lesions has increased significantly, the age of onset of patients tends to be younger, and more and more patients with limited lesions are suitable for radical treatment: radical prostatectomy (RP) or radiotherapy (RT). In the United States, more than 75% of prostate cancer patients presented with clinically limited tumors in 1996, so the proportion of RP and RT has steadily increased, accounting for about 1/3 respectively.
PsA testing plays an important role in the evaluation of the outcome and follow-up of prostate cancer patients. About 1/3 of patients treated radically have elevated PSA within 5 years after surgery, i.e., biochemical recurrence. Biochemical recurrence is currently considered to be the earliest manifestation of disease recurrence and is usually not accompanied by other objective evidence of recurrence. The clinical behavior of patients with biochemical relapse varies widely, with some patients having rapid disease progression leading to death, while some patients present with only an elevated PSA for 5 aro years.
The median time from biochemical recurrence to detection of metastasis after RP is about 8 years, and the median time from clinical metastasis to death is about 5 years. Many studies have shown that the presence or absence of biochemical recurrence in patients after RP is not related to overall patient survival, and it is not a reliable predictor of tumor-specific survival and overall survival. The issues related to biochemical recurrence are described below.
The first problem encountered after RP is that PSA non-O values do not represent a true recurrence of prostate cancer. possible reasons are: residual normal prostate tissue in the prostate fossa or acinus Mu post prostate fossa or anastomosis biopsy confirms the presence of benign prostate tissue in 15% of patients; ectopic prostate tissue in the urethra, bladder, spleen, and anterior hilar space can secrete PSA. the half-life of PSA after RP is 3.coincidentally d, 7 After 7 half-lives, PSA decreases to less than 0.78% of the basal value, and at 21-30 d PSA decreases to undetectable.
Compared with RP, PSA decreases slowly and may not reach unmeasurable levels after RT. The mean half-life of PSA decrease after RT (external irradiation) is 1.9 (0.5 to 9.2) months and 1 to 3 months for brachytherapy, and the slow decrease of serum PSA
The reason for the slow decline in serum PSA is that tumor cells do not die completely until 18-24 months after radiotherapy, and some normal prostate tissue survives and produces PSA after radiotherapy. However, there is no clear correlation between PSA rebound and tumor recurrence. The reason may be that PSA is elevated due to radiotherapy prostatitis or delayed tumor cell death. Of course a non-zero PSA value after RP indicates the possibility of residual lesions.
The PSA biochemical recurrence criteria after prostate cancer surgery is defined as the patient’s serum PSA non-O value, which is usually defined in the literature as a value within the range of 0.2 to 0.6 n to stay ml. 0.4 ng/ml is currently considered the best indicator.
It is recommended that the PSA be tested every 3-4 months for the first 2 years after radiotherapy and every 6 months thereafter. If the PSA drops to the lowest point and increases one by one for 3 consecutive tests, the time of recurrence is set as the midpoint from the lowest point to the first increase, and it is generally considered that 0.sn stay ml is the appropriate indicator.
Once biochemical recurrence is determined, it is first necessary to determine whether there is local recurrence or distant metastasis. Comprehensive judgment measures include:
① Rectal finger examination (DRE):It is difficult to distinguish benign tissue palsy from tumor tissue, 23%-50% of patients with biopsy confirmed local recurrence have no abnormal DRE. After radiation therapy, the DRE cannot accurately determine the local situation due to the contraction of the fibrotic prostate. 25%-65% of patients have tumor remnants but normal DRE. The sensitivity of CT for biopsy confirmation of local recurrence is 36% and local recurrent tumors need to be >2 cm to be detected. asTRO recommends that CT is not used to detect local recurrence when the PSA is <1.5 ng/ml and the value of CT is limited to detecting or monitoring advanced lesions.
The sensitivity and specificity of transrectal MRI for detecting postoperative local recurrence is high, but the current technology has not yet reached real-time MRI-guided biopsy and cannot be pathologically confirmed. MRI is more accurate than radionuclide bone scan (ECT) for detecting skeletal lesions and is earlier than ECT. Changes in prostate tissue due to radiotherapy can affect the identification of internal prostate structure and tumors by MRI.
④ ECT:The rate of positive ECT scan is <5% when PSA does not reach 40 a 50ng/ml after RP surgery, while the PSA level associated with bone scan in patients receiving anti-androgen therapy after surgery is 15ng/ml'The risk of positive ECT results when PSA is <10ng/ml abpendetide. ean) is a radiolabeled prostatic membrane antigen (PSMA)-specific antibody, which has been adopted by the FDA for use in patients with elevated PSA after RP without extraprostatic recurrence detected by conventional imaging methods, but is limited by its sensitivity (83%) and specificity (82%).
Application of transrectal ultrasonography (TRUS) or vesicourethral anastomosis biopsy (VUA):Local recurrence of TRUS after RP often presents as a hypoechoic mass at the urethral-vesical anastomosis, bladder neck, and posterior bladder space, with asymmetric anastomosis or incomplete post-anastomotic level, but 30% of recurrences are isoechoic causing TRUS difficulties with a sensitivity of 76% to 97% and specificity of 26% to 44 PSA <0.sn up ml when positive rate 28%, >Zn years old ml for, O%.
However, TRus does not exclude distant metastases and there are false negatives. Biopsy is feasible when TRUS has suspicious lesions, but 28% of patients require more than 2 biopsies for final diagnosis. The relevant factors to be considered when paying attention to biochemical recurrence include: preoperative PSA level, pathological stage, Gleason score (biopsy and resection specimens), margins, lymph nodes, seminal vesicle involvement, perineal invasion and tumor size.
Local recurrence was suggested in patients with elevated PSA after RP when Gleason score <7, seminal vesicle negative, lymph node negative, PSA elevation time] l years, PSAV <0.75 ng/ml, PSADT] 6 months; and Hyatt eason score] seminal vesicle positive, lymph node positive, PSA elevation time.
In the past 10 years, PSA doubling time (PSADT) has become an important tool to determine disease recurrence after radical treatment of limited prostate cancer. PsADT and Gleason score are strong predictors of disease progression, and PSADT can be used to predict the time to death after radical surgery and radiotherapy in prostate cancer patients, and those with PsADT < 3 months have a higher risk of dying from prostate cancer is 20 times greater than the risk for those with >3 months.
For patients with biochemical recurrence with only a propensity for local recurrence, salvage RP after radiotherapy, radiotherapy of the prostate fossa after RP, cryotherapy, and brachytherapy are all effective treatment options available, and for those with distant metastases androgen removal is the main option, combined with consideration of the patient’s age, physical condition, and comorbidities. astro recommends:PSA >1.5ng/ml and does not necessitate histological evidence, usually more than 80% of patients are effective for salvage radiotherapy after radical surgery (PSA should decrease more than 50%).
Patients with Gleason score) 8, positive seminal vesicles and lymph nodes, and biochemical recurrence within l years after surgery radiotherapy is not significant. The PSA value before radiotherapy is an important indicator affecting the efficacy of radiotherapy, generally PSA <2.0ng/ml is good for radiotherapy, 80% can maintain a tumor-free state for 4 years, while) 2.ong/m1 only 31%, the radiotherapy dose should be >64 a 66Gy. precise radiotherapy three-dimensional conformal irradiation (3D a CRT) and intensity-modulated conformal radiotherapy (IMRT) and other new radiotherapy means can significantly reduce the complications of radiotherapy Complications of radiotherapy, such as bladder irritation, urinary incontinence, hematuria, diarrhea, proctitis, etc., can be significantly reduced.
In cases of local recurrence after radiotherapy leading to biochemical recurrence, salvage radical prostatectomy is most likely to achieve a cure, and salvage surgery at the early stage of recurrence (PsA <10,lg/ml) can result in a 5-year disease-free rate of 66%. However, salvage radical resection after radiotherapy can increase the difficulty of surgery and have more complications than those without radiotherapy. As surgical techniques continue to improve and appropriate patients are selected, complications are significantly reduced and urinary control is restored in about 2/3 of patients. About 28% to 45% of radical prostatectomies that preserve the sexual nerve retain erectile function after surgery.
Salvage cryotherapy and brachytherapy are minimally invasive alternatives to open surgery and are particularly suitable for older patients with complications, but tumor control outcomes are inferior to radical surgery, with a 5-year biochemical control rate (PSA remains low) of 40%, and the incidence of urinary incontinence and erectile dysfunction is no less than that of open surgery.
Traditionally, about 92% of patients with biochemical recurrence after radiotherapy are treated with endocrine therapy, which is only palliative treatment and can be surgical or pharmacological depot, combined with androgen blockade, intermittent androgen blockade, single blockade with anti-androgen drugs, and non-equivalent anti-androgen drugs combined with 5a a reductase inhibitors, but the best method and treatment time need to be further elucidated, and endocrine therapy needs to weigh the treatment and quality of life The relationship between treatment and quality of life needs to be weighed.