Fogorvosi szemle, 2007 (100. évfolyam, 1-6. szám)

2007-10-01 / 5. szám

254

FOGORVOSI SZEMLE ■ 100. évf. 5. sz. 2007.

were 38 % and 32%, respectively, i.e. a total of 70% still were or had been smokers.

DM screening of OC patients

Of patients with OC, 14.6% had DM, whereas 9.7% displayed an elevated fasting blood glucose level, i.e. an overall 24.3% of the patients had abnormal glucose metabolism. Seventy-two of the DM patients were known cases, whereas 17 (2.8%) were newly diagnosed.

In the control group there were significantly fewer DM and elevated fasting glucose cases 5.6 and 5.5%, respectively (p<0.01). The distributions of the malignant tumors in the oral cavity according to location for all of the patients and for the DM group are shown in Table II. The most frequent OC locations among non- DM patients were the sublingual region (29%) followed by the tongue (24%). There were significantly more gingival and lip cancers in the DM group than in the control group (p<0.01).

sions [12, 24, 41], Seventy percent of our DM patients with leukoplakia were or had been smokers. The incidence of 16.6% for premalignant lesions (leukoplakia and erythroplakia) in the smoker OC group was extraordinarily high as compared with data of Albrecht et al. They reported an incidence of 11.5% for leukoplakia among smoking DM patients [2], It may be stated that smoking and DM together are high-risks from the aspect of oral premalignancies.

The other aspect of our study was the DM screening of 610 inpatients with oral squamous cell carcinoma. There were significantly more patients with an abnormal glucose metabolism (DM+EFG) in the tumor group (24.3%) than in the control group (11.1%) (p< 0.01). Among the 89 OC patients with manifest diabetes, DM2 was predominant (97%).

The incidence of oral premalignancies and malignant tumors is higher in persons of disadvantageous social status, as they are more likely also to have un-Table II:

Occurrence of ora! cavity cancers among DM and non-DM patients

Location of oral cavity cancers

Group of patients

Labial

Lingual

Sublingual

Gingival

Buccal

Other

Total

Non-DM patients

73 (14%)

100 (19%)

146 (28%)

83 (16%)

21 (4%)

98 (19%)

521 (100%)

DM patients

21 (24%)

16(18%)

13(15%)

26 (29%)

3 (3%)

10(11%)

89 (100%)

Total

94 (100%)

116(100%)

159 (100%)

109 (100%)

24 (100%)

108 (100%)

610(100%)

Date are n (%)

Our stomato-oncological screening study clarified a higher incidence of benign tumors and precancerous lesions in DM patients. Our examinations revealed a higher incidence of benign tumors than reported by other authors. Bánóczy et al. found a frequency of 3.7% for the most common benign oral lesions [4], This was substantially lower than the 14.5% among our DM patients (10.9% for those DM1, and 16.9% for DM2 patients).

Albrecht et al. found leukoplakia in 6.2% of their DM patients, whereas in our study, an incidence of 6% for leukoplakia in DM patients was observed [2]. Of the 16 precancerous lesions that were screened out, 4 proved to be erythroplakia, i.e. 2% of the 200 diabetes patients. This is markedly higher than the literature value of 0.1% [13].

The incidence of both precancerous lesions (leukoplakia and erythroplakia) was 8% in our DM patients: 3.6% in the DM1 and 11% in DM2 group. This value is essentially higher than the data of other Hungarian authors, who screened the general population for premalignant lesions [4],

The study confirmed the well-known fact that smoking is a deciding risk factor for precancerous oral lediagnosed or insufficiently treated DM [19], The inadequate dental state, the poor oral hygiene and some dietary factors are also independent risk factors for OC, which may be deteriorated by DM [50].

Concerning the location of oral malignancies, in the non-DM group, the lingual and sublingual tumors were predominant. In the DM group, the most frequent locations of cancer were the gingiva and the lower lip, which are also preferentially affected by atrophic and inflammatory lesions in DM patients.

The precancerous and tumorous oral lesions are more frequent among DM2 cases than DM1 ones. A possible etiological factor may be the insulin resistance, the decreased sensitivity of peripheral tissues to insulin [6]. Another important fact that DM2 cases are generally diagnosed and treated after a longer delay, as the complaint-free latency period can take several years [15].

Insulin resistance is a proven risk factor for colorectal, breast, pancreas, prostate, liver and kidney cancers and has a predictive role in the development of oral cavity cancers as well [1, 6, 16, 18, 29, 40, 55, 57, 60].