Case information.
Epidemiology.
The incidence of bilateral synchronous renal cell carcinoma (BSRCC) is low, accounting for about 1%-4% of disseminated renal cancers, but the incidence is as high as 83% in some familial genetic diseases, such as: hereditary papillary renal carcinoma, Von Hippel- Lindau syndrom (VHL), familial clear cell carcinoma and familial renal adenoma. The current bulk case report on renal cancer abroad shows that the incidence of bilateral concurrent disseminated renal cancer accounts for only 1.3% of the incidence of renal cancer.
Definition: Simultaneous disseminated bilateral renal cancer refers to the discovery of simultaneous tumor lesions in both kidneys at the time of consultation or the discovery of lesions on one side at the time of consultation, and the discovery of malignant tumors in the opposite kidney within one year of follow-up (including one year).
Diagnosis.
There is no difference in clinical symptoms and diagnostic tests between bilateral kidney cancer and common kidney cancer. ultrasound, CT and MRI and other imaging examinations are the main means of diagnosis. Ultrasound examination is non-invasive, convenient and inexpensive, and can detect tumors of 1cm in diameter in kidney, but ultrasound examination is easy to miss the diagnosis of multiple lesions, and is often the first choice for tumor screening and postoperative review. MRI examination has the advantage of high soft tissue resolution compared with CT examination, which can clarify tumor stage, determine whether there is metastasis and determine whether there is renal vein and inferior vena cava tumor embolism.
Treatment.
Surgery is the preferred treatment. The main surgical methods include radical nephrectomy (RN) and nephron-sparing surgery (NSS), and there is no specific standard for the surgical treatment and the order of treatment, but there are different opinions. The most beneficial treatment option is NSS.
Jason Rothman, through a retrospective analysis of bilateral renal occupying lesions, concluded that “Masses that disseminate simultaneously in both kidneys are more likely to be malignant, and if one side of the mass is malignant, the other side is malignant 84-95% of the time; the odds of one side being benign are 39-67% of the time that the other side is also benign”. Based on this consideration, bilateral staged surgery is a good choice for making a clear diagnosis and deciding on a reasonable treatment plan.
There are two views on the order of surgery: the first one is that if one side is clinically clear as kidney cancer and cannot be operated to preserve kidney unit, according to the principle of treatment, radical treatment of kidney cancer should be performed sooner or later, because any NSS surgery has the possibility of total kidney resection, so it is believed that which side is operated first has little influence on the prognosis, and early surgery can avoid further development of larger tumor and even cannot be resected radically. The second view is that if one side of the kidney is operated on, the tumor can be removed. The second viewpoint is that if one kidney tumor needs to be radically resected and the other side is smaller, NSS surgery is theoretically feasible, and if NSS surgery is performed first, the remaining kidney function on the other side may be beneficial to postoperative recovery.
Yue-You Liang et al. reported the treatment experience of simultaneous malignant lesions in both kidneys, and concluded that the order of surgery should be decided according to the general condition of the patient before surgery, the total renal function and the size of the tumor on the larger side. “If the patient’s general condition is poor and cannot tolerate longer surgery, radical surgery of one side of the kidney tumor should be performed, and after the patient’s condition is stabilized, the opposite side of the kidney tumor should be resected in the second stage as soon as possible. Frank Becker et al. also suggested that “it is better to operate in two steps, because the side with the tumor can help the kidney recovery on the side with NSS. If NSS is successful on one side, NSS or radical resection on the other side may be an option”.
In a recent foreign retrospective analysis of 220 cases of bilateral concurrent renal cancer, 134 cases underwent NSS successively, 60 cases underwent NSS on one side first and then RN on the other side, 26 cases underwent RN on one side first and then NSS on the other side, and the basic preoperative conditions of the two groups were approximately the same in statistical comparison. There were no statistical differences in terms of recurrence, and the authors concluded that there was no effect on postoperative renal function in the sequence of radical and partial nephrectomy for renal cancer.
Type of pathology.
Mu Dawei et al. conducted a retrospective study of a total of 2,786 patients with renal cancer seen at Peking University First Hospital from April 1986 to December 2009, excluding patients with unilateral renal cancer and hereditary double renal cancer, and a total of 59 patients with bilateral sporadic renal cancer. of the 59 patients, 42 were men and 17 were women, and there were 122 tumors, of which 106 had pathological findings. 99 were clear cell carcinoma , 4 were papillary renal cell carcinoma.
In 1997, the International Union Against Cancer (UICC) and the American Joint Committee on Cancer (AJCC) classified kidney cancer into clear cell renal cell carcinoma, papillary renal cell carcinoma, and smoky renal cell carcinoma based on known genetic alterations and tumor cell origins, combined with morphological characteristics of tumor cells. carcinoma, chromophobe renal cell carcinoma, and carcinoma of the collecting ducts. About 4%-5% of renal cell carcinomas have variable cell morphology and genetic changes, mixed cellular components or unidentified cellular components, and these tumors are classified as renal cell carcinoma unclassified.
In this case, the patient had papillary renal cell carcinoma on the right side and clear cell carcinoma on the left side.
Renal clear cell carcinoma, or conventional renal cell carcinoma or non-papillary renal carcinoma, accounts for approximately 70% to 80% of cases and is the most common pathological type, originating from the proximal tubule of the kidney. Well-defined genetic alterations are characterized by 3p deletion, VHL gene mutation, methylation or deletion, in addition to less well-defined alterations.
Papillary renal cell carcinoma, or chromophobe renal cell carcinoma or tubular papillary carcinoma, accounts for approximately 10% to 15% of cases and is the second most common renal malignancy, probably originating from the proximal tubule. Genetically, it is characterized by loss of Y chromosome and triploidy or tetraploidy abnormalities of chromosome 7 and 17.
Prognosis.
It remains controversial whether the prognosis of bilateral renal cancer is worse than that of unilateral renal cancer. by analyzing 71 patients with concurrent bilateral renal cancer, Blute et al. found that the local recurrence rate, metastasis rate and tumor-free survival in this group of patients with concurrent bilateral renal cancer were not statistically significant compared with unilateral sporadic renal cancer. the study by Patel et al. also did not find a prognosis between bilateral and unilateral renal cancer that was Statistical differences were found. In two earlier studies, Novick et al. and Marberger et al. reported that the prognosis of bilateral renal cancer was worse than that of unilateral sporadic renal cancer, with a 5-year CSS of approximately 38-48%, while in another earlier study, Jacobs et al. found a 5-year CSS of 69% in 61 patients with bilateral renal tumors who were treated surgically at long-term follow-up, which was higher than that of unilateral sporadic renal cancer.
Summary.
The incidence of bilateral sporadic renal carcinoma is low, and renal clear cell carcinoma is the most common histopathological type of bilateral sporadic renal carcinoma. The main treatment modality for bilateral sporadic renal carcinoma is surgery and NSS should be used as much as possible. there is no evidence of a difference in prognosis between bilateral sporadic renal carcinoma and unilateral renal carcinoma.