Introduction
Specific cancers, such as stomach, colorectal, and esophageal cancers, are increasing in the elderly population [8]. Chronicity causes cancer to be transferred to home care. Currently, family members often play a central role in identifying the needs of cancer patients and providing primary care [10]. For cancer patients, maintaining quality of life and preventing negative effects are key priorities, making proper care and attention critically important [13]. Treating the physical and mental health of caregivers who care for cancer patients is an important public health issue [11]. However, the evidence indicates that the pressure to take care of this group of patients has been less studied [14]. Therefore, this study determines the relationship between family caregiving pressure and quality of life in caregivers of elderly patients with digestive system cancers referred to hospitals in Tehran City, Iran, in 2023.

Methods and Materials
This was a descriptive-analytical study conducted in 2023. In this study, the relationship between caregiver burden and quality of life was investigated in 270 caregivers of elderly patients with digestive system cancers referred to selected hospitals in Tehran City, Iran, in 2023. Inclusion criteria for family caregivers in the study were as follows: being the primary companion of the patient at the time of the research (including spouse, child, or sibling); being 18 years of age or older; providing care to patients aged 60 years or older with digestive system cancers; willingness to participate in the study; ability to read, write, and speak Persian; and not simultaneously caring for other physically or mentally ill family members at home or in the hospital. Meanwhile, additional criteria included no history of psychoactive drug use or drug addiction, no current COVID-19 infection, and actively providing care to elderly patients with gastrointestinal cancers during the research period. Participants were also required to have spent at least 10 h per week caring for the patient. Sampling was conducted using probability proportional to size from March to December 2023. In this research, demographic questionnaire, Zarit care burden questionnaire, and cancer caregiver quality of life index was used. Data analysis was done using SPSS, software, version 22. Descriptive statistics, one-sample t test, univariate linear regression, and multivariate linear regression were analyzed, and P<0.05 was considered significant in all stages.

Results
The average score of caregiver burden of elderly patients with gastrointestinal cancer was 30.63±14.10, indicating the average care burden in the caregivers of elderly patients with gastrointestinal cancer (P<0.001). The average score of quality of life in caregivers of elderly patients with gastrointestinal cancer was 70.39±18.12, showing a low quality of life score (P<0.001). A significant negative correlation was found between caregiver burden and quality of life (P<0.001). With the increase in care burden, the quality of life of caregivers of elderly patients with digestive system cancer decreases, and the contribution of care burden to the quality of life of caregivers was 30%. Measuring the impact of demographic variables related to care on the quality of life of caregivers of gastrointestinal cancer patients, with the step-wise multiple linear regression method, showed that with each year the caregiver’s age increases, the quality-of-life score increases by 0.18 on average (P=0.026). 
With the increase of each child, the quality-of-life score increases by about 95 points on average (P=0.001). The effect of demographic variables related to the elderly on the quality of life of caregivers of patients with gastrointestinal cancer, with the step-wise multiple linear regression method showed that with each year the age of the elderly increases, the quality of life of caregivers increases by 1.220 on average (P=0.007). In the elderly who used to smoke every day, the caregiver’s quality of life score was on average 8.367 points higher than that of the elderly who never smoked (P=0.002). In the elderly subjects who were suffering from upper and lower digestive system cancer, compared to the elderly suffering from liver and gallbladder cancer, the quality of life of the caregivers increased by 9.563 and 6.259 units, respectively (P<0.001; P=0.035). The quality of life was 10.048 and 23.760 units higher in the elderly who were in the third and fourth stages of cancer compared to the elderly who were in the first stage (P=0.001; P<0.001). Also, the quality of life of caregivers was lower by 7.413 units in the elderly who received chemotherapy treatments compared to the elderly who did not receive any treatment (P=0.012) (Figure 1).
Conclusion
The family caregivers of the elderly with gastrointestinal cancer suffer from an increase in the existing burden of care, which reduces their quality of life and deteriorates their health. Gastrointestinal cancers are one of the leading causes of death worldwide, in addition to causing significant physical and mental suffering to the patient, they also involve primary care providers. Supporting caregivers is not only about maintaining their well-being, but also has broader implications for overall health and resilience in society and public health. Considering that Iran is moving toward an older population, and with the increasing number of elderly people with cancer, family caregivers should be considered. The evidence shows that currently most of the attention of the nurses in the hospital is focused on the patients, and little attention is paid to the needs of the family members of the patients. Nurses working in the hospital can make a significant contribution in educating families about these departments and also providing psychological support to these families.

Ethical Considerations
Compliance with ethical guidelines
This study was approved by the Ethics Committee of Shahed University Research Vice- Chancellor (Code: IR.SHAHED.REC.1401.006). The study objectives and methods were explained to the participants. They were free to leave the study at any time and were assured of the confidentiality of their information.

Funding
This article is an excerpt from Faezeh Shahri’s thesis, which was approved by Shahed University’s Vice-Chancellor for Research. This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Authors' contributions
All authors equally contributed to preparing this article.

Conflicts of interest
The authors declared no conflict of interest.

Acknowledgments
The researchers express their gratitude to the research assistant of Shahed, Tehran, Iran, and Shahid Beheshti universities, the officials and respected personnel of the selected hospitals, and the family members of the patients participating in this study for their patience and trust.


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