Variation in treatment modalities, costs and outcomes of rectal cancer patients in Poland

Introduction

Many studies have shown important variations in the treatment modalities and outcome between hospitals [1, 2]. The regional and between-hospital differences can only partially be explained by the different volume and case mix that every hospital manages [3].
In Poland, colorectal cancer incidence and mortality are on a steady rise in almost all regions [4]. The implementation of national guidelines, which has been shown in other countries to improve outcomes in rectal cancer [5], has been introduced in Poland. Unfortunately, even with the implementation of the Polish national guidelines for the treatment of colorectal cancers, there are important regional differences in terms of adherence to the guidelines and outcomes of treatment.
In the literature there are conflicting data on whether the differences in treatment modalities of patients with rectal cancer influence outcome. An association between hospital volume and outcome has been reported by some and denied by others [6–10]. Also the analysis of the type of hospital (university hospital, community or county hospital) has shown conflicting results [11, 12].
In this study we analyzed regional differences and outcomes in the treatment modalities used to treat rectal cancer patients. We also tried to identify which factors are responsible for the differences in overall survival between regions.

Material and methods

In Poland, all newly diagnosed cancers should be registered in the nationwide National Cancer Registry. The data are provided by all hospitals at the moment when a new cancer case is diagnosed, and at the same time the cancer should be staged according to the newest version of the TNM classification [13]. On the other hand, the National Health Fund (Narodowy Fundusz Zdrowia, NFZ) is obliged to ensure and cover the costs of treatment of all patients within the system. There is only a small number of oncological patients treated out of this system. To allow for analysis of the costs borne by the system and the results of treatment, a series of coding systems are used for every patient. For coding of the tumor site and type the International Classification of Diseases is used [14]. Unfortunately, there are no data on cancer stage in the system yet. The calculation of the costs is based on the same data. The law in Poland does not require the national insurer (NFZ) to cover the actual costs of a procedure.
The outcomes of patients with colorectal cancer treated in 2005–2007 were compared to those treated in 2000–2002. We compared results for the colon and rectal cancer group as a whole because there was no information about 5-year survival rates of the subgroup of rectal cancer patients treated previously. Survival data from the years 2000–2002 were obtained from the National Cancer Registry, as there were no similar data available from the National Health Fund.

Statistical methods

For statistical analysis we used Statistica 10 for Windows. Univariate and multivariate analysis of the available data was performed.

Patients

In Poland 41,287 patients were diagnosed with colorectal cancer from 2005 to 2007. Data of all patients with invasive rectal cancer diagnosed and treated between 2005 and 2007 within the National Health Fund system in Poland were selected for the study (n = 15,281).

Regions, hospitals, surgeons

Poland is divided into 17 regions (voivodeships). There exist important differences between regions in terms of population, income per capita and centralization of cancer care (not all regions have a dedicated cancer center). Also, in regions with a dedicated cancer center not all cancer patients are treated there, as many patients are treated in university and community or county hospitals. In Poland there is a subspecialty called surgical oncology, and the majority of surgical oncologists are general surgeons with two additional years of training in cancer centers. However, there is no legal obligation that would require all cancer patients to be treated by surgeons with this particular subspecialty. Some of the operations for rectal cancer are performed by general surgeons and some by surgical oncologists (who are also general surgeons).

Results

Survival

Colorectal cancer

Relative 5-year survival was 52.8% for the whole colorectal patient group treated between 2005 and 2007 (ranging in voivodeships from 48.1% to 56.1%). Comparison (Fig. 1) of current and historical data for all regions in Poland shows an important rise in the outcomes. Five-year survival in the years 2000–2002 was 43.7% and ranged depending on the region from 36.3% to 45.7%. When comparing data for each region separately for both periods we found that rates rose for every region from 8% to 12.5% (mean rise of 9.1%).

Rectal cancer

There was an 8.4% difference in relative 5-year survival rate between Polish voivodeships (47.1% to 55.5%; mean 51.6%) (Fig. 2).
Radiotherapy was used in 47.5% of patients (33.5% to 59.4% depending on the region, Fig. 3). The use of radiotherapy in each region did not influence overall 5-year survival rates (p = 0.26) (Fig. 4).
Chemotherapy (adjuvant or neoadjuvant) was used in 60.7% (51.4% to 75.3% depending on the region) of patients (Fig. 5). The use of chemotherapy in each region did not influence overall 5-year survival rates (p = 0.28) (Fig. 6).
Surgery with curative intent was performed in 64.1% (45.5% to 70.6% depending on the region) of patients (Fig. 7). We observed a trend toward better survival rates in regions with more radical surgery cases, although this trend did not reach the level of statistical significance (p = 0.07) (Fig. 8).
Analysis of percentages of hepatic metastasectomies performed in rectal cancer patients showed significant differences between voivodeships; mean 1.5% (range 0.25–2.5%) (Fig. 9).
We also looked at the mean number of rectal cancer patients per surgical oncologist in each region. These numbers showed important variations among regions and ranged from 28 to 114 patients/specialist (mean 50) (Fig. 10). We did not find a statistically significant relation but only a trend between the number of patients per surgical oncologist per region and the 5-year overall survival rate (p = 0.07) (Fig. 11). It is important to note, however, that this number does not represent the actual workload of each surgical oncologist but only the number of patients in a particular region divided by the number of surgical oncologists practicing in this region, without taking into account the number of general surgeons and coloproctologists who take care of these patients.

Costs

The mean cost of treatment of rectal cancer patient was 32,800 Polish zloty (PLN) (7,800 EUR; EUR = 4.2 PLN) (Fig. 12). Mean cost of surgery was 6500 PLN (1540 EUR), mean cost of radiotherapy was 7200 PLN (1700 EUR) and of chemotherapy was 18,300 (4340 EUR). The differences between regions in the mean costs of treatment were important and ranged from 29,300 PLN (6,900 EUR) to 38,500 PLN (9,140 EUR). The different costs of treatment in each voivodeship were analyzed to find whether there is a relation between cost of treatment and overall survival in a region. When data for all regions were compared, we found no statistically significant differences in terms of 5-year survival rates for each region (Fig. 13). Interestingly we also failed to find a statistically significant correlation between the cost of treatment in each region and the incidence of chemotherapy (adjuvant or neoadjuvant), radiotherapy or surgery.

Discussion

In this nationwide population-based study evaluating National Health Fund data of 15,281 patients with rectal cancer diagnosed and treated in Poland in the period from 2005 to 2007, we found important differences in treatment modalities and outcomes between regions.
The relative 5-year survival rate of 52% observed in this analysis is disturbingly lower when compared to the figures from the USA (66%) [15], the United Kingdom (56%) [16] or Norway (66%) [17]. On the other hand, only a few years ago the figures for 5-year survival were much lower for all regions and rose by an average of 9.1% during this time span. This important step forward can be partially explained by the introduction of the guidelines in the treatment of rectal cancer, which has been shown to improve outcomes [5].
The current standard of care in Poland requires that for the treatment of rectal cancer patients with stage III and locally advanced stage II tumors without distant metastasis receive radio-chemotherapy or radiotherapy preceding resection to reduce the risk of local recurrence [18]. In our study we found important variations between regions in terms of incidence of radiotherapy ranging from 33.5% to 59.4%. While the higher numbers are similar to numbers in other national data sets (USA 50%, The Netherlands 54%) the numbers for some Polish regions are definitely too low, even taking into account a different case mix. The differences in the approach to preoperative radiotherapy between surgeons and hospitals despite clear and unified national criteria are a constant finding in other publications. A Korean questionnaire study showed that surgeons in university hospitals are more likely to refer patients with rectal cancer for preoperative radiotherapy [19]. However, Dutch results showed that patients diagnosed in a teaching hospital were less likely to receive preoperative radiotherapy [3].
Interestingly, we could not find a statistically significant correlation between the incidence of radiotherapy in a region and probability of overall survival. This finding can be explained by reports confirming that preoperative radiochemotherapy can indeed lower local recurrence rate but at the same time may have no influence on overall survival [20]. However, it should be underlined that in our study we did not analyze the influence of regional differences in case mix on the outcome. Thus, it is possible that the differences in incidence of radiotherapy mirror important differences in the tumor burden in each regional patient population.
Similar disparities were observed between regions in terms of chemotherapy treatment. Once again, we observed no statistically significant correlation between chemotherapy treatment and overall survival probability in each region. Adjuvant and neoadjuvant chemotherapy has been shown to influence both disease-free [21] and overall survival [22]. Therefore, our results probably reflect the differences in the stage of the disease between regions.
The high variation in the incidence of surgery with curative intent (45.5% to 70.6% depending on the region) is probably a reflection of different stage of disease as well. But this is only a partial explanation. One should bear in mind that even currently in Poland about 50–60% of cases of colorectal cancer are diagnosed and treated at stage III and IV [4]. The influence of performing surgery with curative intent on overall survival was the strongest single factor influencing survival in our study, but it did not reach statistical significance.
Another factor that showed a trend toward reaching statistical significance was the impact of the mean number of rectal cancer patients per surgical oncologist in each region on survival. This finding is difficult to interpret due to the specific nature of this subspecialty in Poland and the fact that many general surgeons without formal surgical oncology training perform rectal cancer surgery as well. It seems likely that these two findings (surgical resection percentages and number of patients per specialist with their influences on survival) may indicate differences in quality of treatment of rectal cancer patients.
Another finding that came as a surprise was the low incidence of hepatic resection in the study group. The 1.5% of rectal cancer patients undergoing liver resection for metastasis is much lower than the 6.1% reported in the North American study on Medicare beneficiaries [23]. This number seems very low. It is not clear why so few rectal cancer patients underwent hepatic resection. One explanation could be the low number of dedicated hepatopancreaticobiliary (HPB) centers in Poland (currently only 6 centers in Poland have an advanced HPB and liver transplant program).
The cost of treatment of rectal cancer patients in Poland was significantly lower than the same costs in Poland’s western neighbor, Germany. The mean of 7,800 EURO paid in Poland is far from the 15,000 EURO to 21,300 EURO for early stages and from 29,800 EURO to 35,000 EURO for late stages reported by the German insurance system [24]. Similar numbers have been reported in France, where the mean cost of a year of treatment of a colorectal cancer patient has been found to be 24,966 EURO. The French analysis also showed the influence of stage on the total cost of care, with cost of treatment of stage I colorectal cancer of 17,596 EURO and 35,059 EURO for stage IV [25]. In our study no correlation was found between the cost of treatment of a rectal cancer patient in each region and the overall survival. Interestingly, we also failed to identify a correlation between higher cost and the probability of chemotherapy, radiotherapy or curative surgery treatment. While we cannot fully explain these findings, it is somewhat reassuring that lower costs of treatment in some regions in our study were not correlated with poorer survival.
In conclusion, despite the existence of the national treatment guidelines in Poland, there are important disparities between regions in terms of type of treatment, overall survival and costs. In the last few years we have observed a major improvement in the results of treatment of rectal cancer, but they are still worse than the results in the USA and Western Europe.

The authors declare no conflict of interest.

References

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Address for correspondence

Andrzej L. Komorowski, PhD
Department of Surgical Oncology
Maria Skłodowska-Curie Memorial Institute
of Oncology Cancer Centre
e-mail: alkomorowski@wp.pl

Submitted: 08.10.2014
Accepted: 20.04.2015