[Abstract] Objective To investigate the survival results of bilateral primary breast cancer (Bilateral Primary Breast Cancer, BPBC) and its prognostic factors. Method retrospectively analyzed the clinical data of patients of the admitted BPBC Tianjin Medical University Cancer Hospital from March 1972 to December 2003. Results BPBC (survival time) calculated from the second surgery date five years, the 10-year cumulative survival rates were 78.73% and 69.09%. In simultaneously sexual BPBC (Synchronous BPBC, sBPBC) and metachronous BPBC (Metachronous BPBC, mBPBC), 5-year cumulative survival rate, 10-year cumulative survival rates were 70.87% and 82.07%, 62.99% and 71.83%, the survival rate of sBPBC the overall than mBPBC difference, but not statistically significant. The second side of the lymph node-negative patients, 5-year, 10-year cumulative survival rate was 88.19%, 76.50%, respectively. Node-positive patients, 5-year, 10-year cumulative survival rates were 61.13% and 54.79% (P <0.01), the difference was statistically significant. Starting side lymph node-negative patients, 5-year, 10-year cumulative survival rates were 85.69% and 79.98%, lymph node-positive patients five years, 10-year cumulative survival rates were 65.38% and 50.21% (P = 0.0002), the difference was statistically significance. The second side tumors greater than 5 years equals 5cm patients, the 10-year cumulative survival rate of 42.92% and 36.79%, respectively. The second side of the tumor is less than 5cm in patients with 5-year, 10-year cumulative survival rates were 83.18% and 74.22%, respectively, and the difference was statistically significant. Conclusion At the same time and metachronous BPBC, survival rate is similar to the second side of the tumor is greater than or equal to 5cm, bilateral lymph node-positive poor prognosis. Multivariate analysis revealed that tumor size and the first side of the second side, the second side with node-positive prognostic factors.

Key words double bilateral primary breast cancer prognosis

1 objects and methods

1.1 The object of study: March 1972 to December 2003 bilateral primary breast cancer were treated breast cancer patients are women. 6个月），占68.92%。">Which sBPBC 69 cases, accounting for 31.08%; the mBPBC, 153 cases (occurs on both sides time interval of> 6 months), accounting for 68.92%. The survival period is the start to the second side of the day of surgery, until death, recurrence, metastasis or last follow-up time. Secondary onset interval is twice the second date of admission to the first surgery date.

1.2 follow-up and statistical methods

Outpatient followed up the cases recorded, the petition registration Telephone inquiries are three ways to follow-up, follow-up date for March 2006. Application SPSS10.0 statistical package for statistical analysis, the survival rate calculated using the method of Kaplan Meier Analysis of prognostic factors using Cox univariate and multivariate analysis, prognostic factors grouped data using the Kaplan-Meier method and the Log-Rank test.

2 Results

2.1 incidence:

As of the end of December 2003, 20,308 breast cancer patients admitted to the same period in the Cancer Hospital found 222 cases BPBC patients, the BPBC patients was 1.09%, which sBPBC69 cases, the rate was 0.34%, mBPBC153 cases, the incidence of 0.75%.

2.2 follow-up results:

The follow-up to the end of March 2006, 49 cases of death in the follow-up, 49 patients had distant metastases. Shortest follow-up time was 51 days, up to 7520 days, an average of 2,059 days. The total mortality rate was 22.07%, the survival rate of patients are shown in Table 1, the survival curve is shown in Figure 1. Table 1 222 cases of bilateral primary breast cancer survival rate changes

2.3 Analysis of prognostic factors

2.3.1 simultaneous and metachronous and prognosis of 69 cases of sexual primary double breast cancer patients, 18 cases of death, the mortality rate was 26.09%; 31 cases of death in 153 cases of metachronous primary double breast cancer patients The mortality rate was 20.26%. P <0.05, this result was not statistically significant. The patients with sBPBC and mBPBC cumulative survival rates compared in Table 2: Table of 2 sBPBC and the mBPBC cumulative survival rate between the Log rank statistical value of 1.01, P = 0.3157, not statistically significant. the survival rate overall compared sBPBC mBPBC the poor, but not statistically significant.

2.3.2 starting side of positive lymph nodes and prognosis

141 cases of first side 22 cases death occurs in the lymph node-negative patients, the mortality rate was 15.60%; 27 cases of death in 78 cases the first side of the lymph node-positive patients, the mortality rate was 34.62%. P = 0.001, <0.05, the results are statistically significant. The first side of the lymph node negative group and the first side of the node-positive group cumulative survival rates compared in Table 3: Table 3 starting side node-negative group and the first side of the Log rank statistical value of positive lymph node group 14.36, P = 0.0002, there is statistically significant. Node-negative group good prognosis in node-positive group.

2.3.3 The second side of positive lymph nodes and prognosis

The second side of the 142 cases of lymph node-negative patients, 21 cases of death, the mortality rate was 14.79%; 75 cases of the second side of the side of the 27 cases of death in lymph node-positive patients, the mortality rate was 36.00%. P <0.05. The second side of the lymph node negative group and the second side of the node-positive group cumulative survival rates compared in Table 4: TABLE 4 second side of the lymph node negative group and the second side of the lymph node positive group Log rank statistical value of 16.92, P = 0.0000 statistics significance. Node-negative group good prognosis in node-positive group.

2.3.4 second side of the tumor size and prognosis

183 cases of the second side of the tumor <5cm patients, 32 cases of death, the mortality rate was 17.49%; 30 cases of the second side of the tumor ≥ 5cm patients, 16 cases of death, the mortality rate was 53.33%. P <0.05. The second side of the tumor <5cm group and the second side of the tumor ≥ 5cm cumulative survival rates comparison are shown in Table 5: Table 5 second side of the tumor <5cm and second side tumor ≥ 5cm Log rank statistical value 28.36, P < 0.05, statistically significant. Prognosis than the second side of the second side of the tumor ≥ 5cm group tumor <5cm difference.

2.3.5 multi-factor analysis univariate analysis significant the sexual variables into the Cox model for multivariate analysis, and the results are shown in Table 6: Table 6 prognostic factors Cox regression multivariate analysis, bilateral lymph node status and the second side tumor size affect prognostic factors BPBC. According to the results of the multivariate analysis, the survival model fitting BPBC patients: h (t, x) = H0 (t) exp ( 0.666X1 +1.007 X2 +0.167 X3) X1: the first side of the node-positive X2: The second side node-positive side X3: tumor size

3 Discussion

3.1 survival rate

A review of published literature in China, the five-year survival rate from 28.4% -86.6% 10-year survival rate from 21.40% -69.7% (see Table 7), such a large gap and take the sample region, age, income group standard samples mined condition, the length of the follow-up time, statistical methods, and BPBC starting point is based on the first side of the cancer or the diagnosis or surgery as a starting point or as a starting point to the second side of the relationship. Shown in Table 7 Table 75 10-year survival literature compare * second side side breast cancer treatment or diagnosis or surgery or after surgery as a starting point.

Views about the method of calculation of the bilateral primary breast cancer survival rates are not uniform, many scholars from the second side of cancer, some believe that the survival rate calculated from the diagnosis of cancer of the starting side and taking into account the lifetime of the extension of the side of cancer increased risk of this factor is more appropriate [18]. We think in study prognosis of BPBC, the survival rate within the interval of time can not be considered mBPBC survival rate, as calculated from the starting side diagnosis survival rate due mBPBC longer intervals, the outcome is likely to lead to bias , it is suggested that in order to calculate the survival time of cancer diagnosis from the second side is more reasonable. In addition, only when the second cancer after mBPBC patients only from UBC classified to the BPBC. Therefore, as a starting point to the second cancer survival rate was calculated in order to truly reflect the prognosis of sBPBC and mBPBC. The statistical method should be used to the life table method or Kaplan Miere law in order to more accurately reflect [17]. In this paper, the second side of the surgery date as a starting point calculations, Kaplan Miere come to the five-year survival rate was 78.73%, 10-year survival rate was 69.09%.

The 3.2 sBPBC mBPBC survival rate

Abroad, Kollias et al reported, such as survival time is calculated from the second side of the cancer diagnosis, similar to the overall survival of sBPBC and mBPBC (Log-Rank test, X2 = 2.33, P = 0.3100) [19]. Singletary and other reports, the survival rate calculated from the second side of the cancer diagnosis, the two groups were not statistically significant difference in overall survival (Log-Rank test, P = .6316) [20]. Calculate the survival time in the country, in the 54 case studies in Hong Wenshan cancer diagnosis from the second side of the 5-year OS sBPBC, and mBPBC of 49.1% and 54.0%, respectively, 8-year OS was 32.1% and 33.1%, respectively, the difference was not statistically significant, P = 0.5193 [15]. Zhang Tao, of the 217 cases of summary, sBPBC with mBPBC median survival time was 29.6 months, 27.8 months, no significant difference in survival. The second side of the cancer as a starting point to calculate survival rate and the mBPBC the 5-year and 10-year survival rates were 29.5% and 8.4%, sBPBC with mBPBC survival in patients with no difference significantly [17]. Shen town chou analysis of 71 cases, the prognosis reported sBPBC is is worse than mBPBC, but statistically no significant difference [4].

The Heron study found sBPBC mBPBC and unilateral breast cancer (Ulit Breast Cancer, UBC), the 5-year and 8-year survival rates were 83.1% and 78.8%, 97.8% and 91.4%, 93.9% and 85.8%. That mBPBC survival rates similar to UBC superior sBPBC. Simultaneity of bilateral breast the distant metastasis dangerous than unilateral breast cancer and metachronous bilateral breast [18]. Burns and Bailey: the simultaneous bilateral tumor patients and single tumor better prognosis [21,22]. Carmichael and other single factor analysis method to calculate the survival time of cancer diagnosis from the second side display sBPBC 5-year OS (70.7%) than metachronous (76.6%) (Log-Rank test, X2 = 11.39 , P = 0. 0034), but multivariate analysis shows that sBPBC is not an independent prognostic factor [23]. Fung et al reported sexual bilateral breast cancer, 5-year and 10-year survival rates were 84% and 64%, metachronous bilateral breast cancer five years and 10 years, respectively, 98% and 95 % [24]. In the country, has been reported simultaneity of bilateral breast cancer 2 year survival rate (43.8%, 7/16) was significantly lower than metachronous bilateral breast cancer (94.2%, 49/52) [10]. Zhang Tao, the theoretically sBPBC occur within a short interval of time mBPBC carcinogenic factors may be strong or poor function of the body’s immune defenses, and thus its prognosis may be poor [17].

The group of studies have shown that sBPBC overall survival rate than mBPBC poor, but not statistically significant.

3.3 Analysis of prognostic factors

After correction of single factor analysis, and recognized the unilateral breast cancer prognostic factors, tumor size and axillary lymph node status are also major factors affect BPBC prognosis. The second side of the tumor size and axillary lymph node status, as well as the first side of axillary lymph node status influence on the prognosis. The first and second sides of the axillary lymph nodes, the second side 5cm in low survival rate of patients with tumors greater than or equal to, the average survival time is short, the prognosis is poor.